ccm/sff-papers · Datasets at Hugging Face

['Lewis, Gary K.', 'Milewski, John O.', 'Thoma, DanB.', 'Nemec, RonB.']

2018-12-06T21:12:23Z

1997

Mechanical Engineering

doi:10.15781/T2639KR65

http://hdl.handle.net/2152/71429

eng

1997 International Solid Freeform Fabrication Symposium

Open

['DLF process', 'cross-sectional layers']

Properties of Near-Net Shape Metallic Components Made by the Directed Light Fabrication Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/fbfac1a0-9854-4ce8-9d90-340802869c2b/download

null

['Li, Wenbin', 'Ghazanfari, Amir', 'McMillen, Devin', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Watts, Jeremy']

2021-10-27T23:33:48Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89643

eng

2016 International Solid Freeform Fabrication Symposium

Open

['ceramic on-demand extrusion', 'zirconia components', 'ceramic parts']

Properties of Partially Stabilized Zirconia Components Fabricated by the Ceramic On-Demand Extrusion Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/086f0c86-8919-4400-9f37-dee902358797/download

University of Texas at Austin

The Ceramic On-Demand Extrusion (CODE) process is a novel additive manufacturing process for fabricating dense ceramic components from aqueous pastes of high solids loading. In this study, 3 mol% Y2O3 stabilized tetragonal zirconia polycrystal (3Y-TZP) parts were fabricated using the CODE process. The parts were then dried in a humidity controlled environmental chamber and sintered under atmospheric pressure. Mechanical properties of the sintered parts were examined using ASTM standard test techniques, including density, Young’s modulus, flexural strength, Weibull modulus, fracture toughness and Vickers hardness. The microstructure was analyzed, and grain size was measured using scanning electron microscopy. The results compared with those from Direct Inkjet Printing, Selective Laser Sintering, and other extrusion-based processes indicated that zirconia parts produced by CODE exhibit superior mechanical properties among the additive manufacturing processes. Several example parts were produced to demonstrate CODE’s capability for fabricating geometrically complex ceramic parts.

null

['Qi, Gang', 'Dai, Cheng', 'Rangarajan, Sriram', 'Wu, Suxing', 'Bandyopadhyay, Amit', 'Langrana, Noshir', 'Safari, Ahmad', 'Danforth, Stephen C.']

2018-12-05T20:10:50Z

1997

Mechanical Engineering

doi:10.15781/T2HM5353R

http://hdl.handle.net/2152/71410

eng

1997 International Solid Freeform Fabrication Symposium

Open

['LOM', 'FDC']

Properties of RU955 Si3N4 Filament for Fused Deposition ofCeramics

Conference paper

https://repositories.lib.utexas.edu//bitstreams/01e28703-a3fe-436a-93a5-5b30c5bc3faf/download

null

One ofthe key elements in the FDC process is the development of ceramic loaded fusible filament. The filament is not only material feed stock for deposition, but also serves as a piston to push the fused material through the FDC liquefier. Therefore, the FDC filament has to meet several requirements. It should have enough flexibility to satisfy the automatic feeding requirements, enough stiffness to carry the force for extrusion in the liquefier, and a low viscosity. A series of binders developed at Rutgers University show promising properties and meet these requirements. However, the change of filament properties with time and storage conditions was observed, and they dramatically influenced the FDC process. Systematic experiments were carried out in order to understand filament aging and establish proper storage conditions. The results indicate that moisture in the environment plays an important role in the filament aging. Vacuum treatment at 30°C apparently accelerates the aging process. The mechanisms offilament aging and the method offilament evaluation will be discussed.

null

['Zhang, Shanshan', 'Dilip, Samuel', 'Yang, Li', 'Miyanaji, Hadi', 'Stucker, Brent']

2021-10-21T19:17:51Z

2015

Mechanical Engineering

null

https://hdl.handle.net/2152/89427

eng

2015 International Solid Freeform Fabrication Symposium

Open

['cellular struts', 'process parameters', 'process orientation', 'selective laser melting', 'powder bed fusion', 'additive manufacturing']

Property Evaluation of Metal Cellular Strut Structures via Powder Bed Fusion AM

Conference paper

https://repositories.lib.utexas.edu//bitstreams/7113e701-7306-4132-abe4-3c46df3bece4/download

University of Texas at Austin

Cellular structures are widely used in many engineering applications, because of their light weight, high strength-to-weight ratio, high energy absorption, etc. Many previous research and development works are largely focused on structural design, while the material properties are often over-simplified. In this work, the relationships between process parameter and orientation on the geometrical and mechanical characteristics of the cellular struts fabricated via selective laser melting (SLM) were investigated. The results provide preliminary guidelines on the use of laser melting additive manufacturing process for the fabrication of cellular strut structures.

null

['Moylan, Shwan', 'Slotwinski, John', 'Cooke, April', 'Jurrens, Kevin', 'Donmez, M. Alkan']

2021-10-06T22:37:47Z

8/15/12

Mechanical Engineering

null

['https://hdl.handle.net/2152/88462', 'http://dx.doi.org/10.26153/tsw/15399']

eng

2012 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'standardization', 'test parts', 'test artifact']

Proposal for a Standardized Test Artifact for Additive Manufacturing Machines and Processes

Conference paper

https://repositories.lib.utexas.edu//bitstreams/5a48c9b9-0df0-4b77-8a9d-55b21d820d56/download

University of Texas at Austin

Historically, standardized test parts are used to quantitatively evaluate the performance of a machine or process. While several different additive manufacturing (AM) test parts have been developed in the past, there are no current standard test parts. This paper reviews existing AM test parts, discusses the purposes of the studies, and describes important features and characteristics found in these test parts. A new test part intended for standardization is proposed. This part incorporates the most useful features seen in previous test parts. These features are designed to highlight process capabilities and test machine accuracy. The design has been validated through builds by several AM processes.

null

['Nassar, A.R.', 'Reutzel, E.W.']

2021-10-07T15:16:28Z

2013

Mechanical Engineering

null

['https://hdl.handle.net/2152/88476', 'http://dx.doi.org/10.26153/tsw/15411']

eng

2013 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'XML-based file format', 'ASTM F291 standard', 'digital thread', 'automotive', 'aerospace', 'medical']

A Proposed Digital Thread for Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/439cd274-e7ad-4424-8f93-1b84837f24b0/download

University of Texas at Austin

Additive manufacturing (AM) has been explored by the automotive, aerospace and medical industries for many years but has yet to achieve wide-spread acceptance. This is partially due to the lack of standard frameworks for the exchange of data related to design, modeling, build plan, monitoring, control, and verification. Here, a unified paradigm, built on Extensible Markup language (XML) -based file formats and influenced by the ASTM F291 standard, is proposed, to record and transmit data at every stage of the AM process. This digital thread contains all essential parameters, from design to testing of metal-based AM parts while remaining accessible, traceable and extensible.

null

['Gegesky, Megan', 'Liou, Frank', 'Newkirk, Joseph']

2021-10-28T19:03:53Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89670

eng

2016 International Solid Freeform Fabrication Symposium

Open

['fusion welding', 'friction stir', 'hybrid process', 'part build']

Proposed Hybrid Processes for Part Building Using Fusion Welding and Friction Stir Processing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b49f514d-8ffc-4068-9c48-3e6b3fbabe48/download

University of Texas at Austin

It has been shown that a hybrid laser additive manufacturing and friction stir processing can deposit components with forged-like structures. This paper reports a hybrid fusion welding and friction stir process to create parts with quality structures. Combining traditional fusion welding and friction stir processing techniques for non-weldable aluminum alloys could facilitate the joining of difficult geometries in manufactured parts. This research illustrates mechanical property changes for non-weldable and weldable aluminum alloys. The Vickers hardness, and microhardness in the case of AA5052-H32, tensile strength and corrosion resistance of four processing states: base material, fusion welded material, friction stir welded material, and friction stir processed fusion welded material are studied for AA2024-T351, AA5052-H32, and AA7075- T651. This technology has applications to part building for large parts such as landing gear, and ship hulls; where traditional additive manufacturing processes would be excessively costly and time consuming. By joining larger pieces by such a hybrid process, a near net shape approach can be achieved on a large scale. This technology would remove the need for drilling and fastener use, plausibly increasing the strength of large part joints with complex geometries.

null

['Tang, H. H.', 'Yen, H. C.', 'Su, S. M.', 'Lin, Z. Y.']

2020-02-13T19:45:21Z

9/1/04

Mechanical Engineering

null

['https://hdl.handle.net/2152/79968', 'http://dx.doi.org/10.26153/tsw/6993']

eng

2004 International Solid Freeform Fabrication Symposium

Open

layer manufacturing

Prospect of Making Ceramic Shell Mold by Ceramic Laser Fusion

Conference paper

https://repositories.lib.utexas.edu//bitstreams/dcf9292a-7847-4c0e-8871-863dbd496bdf/download

null

Manufacturing prototypical castings by conventional investment casting not only takes several weeks, but also is prohibitively expensive. Z Corporation in USA, EOS GmbH and IPT in Germany employ the techniques of 3DP and SLS respectively to make directly ceramic shell molds for metal castings. Although those techniques dramatically reduce time expenditure and production cost, each layer cannot be thinner than 50 µm because of using powder to pave layers. The dimensional accuracy and roughness of the castings still cannot meet the specification of precision casting. Therefore, in this paper the ceramic laser fusion (CLF) was used to pave layers. Each layer can be thinner than 25 µm, so that the step effect can be diminished and the workpiece surface can be smoother; drying time will be shortened dramatically. Moreover, the inherent solid-state support formed by green portion has the capability of preventing upward and downward deformation of the scanned cross sections. In order to make shell mold which meets the roughness requirement (Rq=3.048µm) of the precision casting, following issues have to be further studied: (1) design a proper ceramic shell mold structure, (2) design a paving chamber for paving a complete green layer which can be easily collapsed, (3) cut down drying time, (4) optimize laser scanning process parameters with the smallest distortion, (5) eliminate sunken area, (6) reduce layer thickness to less than13µm, (7) control power to guarantee the energy uniformly absorbed by workpiece, and (8) develop a method which can directly clean green portion in cavity from gate.

null

['Jahnke, U.', 'Büsching, J.', 'Reiher, T.', 'Koch, R.']

2021-10-21T20:42:41Z

2015

Mechanical Engineering

null

https://hdl.handle.net/2152/89442

eng

2015 International Solid Freeform Fabrication Symposium

Open

['protection measures', 'product piracy', 'additive manufacturing']

Protection Measures against Product Piracy and Application by the Use of AM

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f24b0223-be6f-4371-acb5-cd07b54c344f/download

University of Texas at Austin

Presently the implications Additive Manufacturing (AM) on intellectual properties are discussed in public. Here AM is often mentioned as a driver for product piracy as it allows to produce and to copy objects with any geometries. Imitators need a lot of information to copy an object accurately. As reverse engineering has been identified as the most important information source for product imitators, AM can also help to reduce the threat of product piracy when correctly applied in the product development. Due to the layer wise production process that allows the manufacturing of very complex shapes and geometries, the reverse-engineering process can be complicated by far. By this, quite contrary to the public opinion, AM can increase the needed effort of imitators and strongly reduce the economic efficiency of product piracy. This paper will show different protection measures and a methodological approach of how to apply these measures to a product. Beside the protective effect some measures allow a traceability of parts over the product’s lifecycle and thus support the quality management of AM processes and additively produced parts.

null

['Lennings, A.F.', 'Broek, J.J.', 'Horvath, I.', 'Smit, A.', 'Vergeest, J.S.M.']

2019-02-19T17:30:18Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73433', 'http://dx.doi.org/10.26153/tsw/585']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['Rapid Prototyping', 'technology']

Prototyping Large-Sized Objects Using Freeform Thick Layers of Plastic Foam

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b2c710ef-67c9-43a4-b41a-5d6800e8e48c/download

null

Current Rapid Prototyping systems are primarily aimed at small-sized objects containing many shape details. In this paper a Rapid Prototyping technology is presented that is aimed at largesized objects having a complex, freeform outer shape. This new technology builds the model out ofthick layers, each having freeform outside faces. The paper will present: an overview of current methods to produce large prototypes, the basics of the new method, the technology used to produce the layers, the toolpath planning and finally the overall system design.

null

['Dordlofva, Christo', 'Törlind, Peter']

2021-11-08T22:53:31Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/90065', 'http://dx.doi.org/10.26153/tsw/16986']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'space application', 'qualification', 'product development process', 'manufacturing process development']

Qualification Challenges with Additive Manufacturing in Space Applications

Conference paper

https://repositories.lib.utexas.edu//bitstreams/2ebb16fe-aa43-44d5-9cdf-67de9734bd38/download

University of Texas at Austin

Additive Manufacturing (AM) has the potential to remove boundaries that traditional manufacturing processes impose on engineering design work. The space industry pushes product development and technology to its edge, and there can be a lot to gain by introducing AM. However, the lack of established qualification procedures for AM parts has been highlighted, especially for critical components. While the space industry sees an advantage in AM due to expensive products in low volumes and long lead-times for traditional manufacturing processes (e.g. casting), it also acknowledges the issue of qualifying mission critical parts within its strict regulations. This paper focuses on the challenges with the qualification of AM in space applications. A qualitative study is presented where conclusions have been drawn from interviews within the aerospace industry. The results highlight important gaps that need to be understood before AM can be introduced in critical components, and gives insight into conventional component qualification.

null

['Weeren, R. Van', 'Agarwala, M.', 'Jamalabad, V.R.', 'Bandyopadhyay, A.', 'Vaidyanathan, R.', 'Langrana, N.', 'Safari, A.', 'Whalen, P.', 'Danforth, S.C.', 'Ballard, C.']

2018-11-02T16:50:57Z

1995

Mechanical Engineering

doi:10.15781/T2CZ32Q6D

http://hdl.handle.net/2152/69339

eng

1995 International Solid Freeform Fabrication Symposium

Open

['CAD', 'SLS', 'SLA process']

Quality of Parts Processed by Fused Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/68b5450e-aa5f-4d71-8d86-7ad86991335e/download

null

FDMTM (fused deposition modeling) is a SFF technique for the fabrication of polymer parts. Research is being conducted on the fabrication of ceramic parts by fused deposition. In this study polymer and ceramic parts were made using a commercially available FDMTM system, 3D Modeler, and the Quickslice™ software. These parts were evaluated for processing defects. Defects originate from the fused deposition process, from material characteristics, or a combination thereof. Process defects, which are present in all polymer parts, are due to current hardware, software and build strategy limitations. These same defects are seen in ceramic parts fabricated by fused deposition of ceramics (FDC). Another set of defects in ceramic parts is due to materials characteristics, i.e., non-uniformities in the feed stock filaments, their mechanical and/or rheological properties. The presence of defects in polymer or ceramic parts was studied using simple build primitives (single roads) and parts in the green state. Parts were characterized for their quality using SEM and optical microscopy.

null

['Weaver, Jason', 'Barton, TJ', 'Jenkins, Derrik', 'Linn, John', 'Miles, Mike', 'Smith, Robert']

2021-11-04T20:10:08Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/90019', 'http://dx.doi.org/10.26153/16940']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['test artifact', 'accuracy', 'capabilities', 'concept laser', 'metal additive manufacturing', 'NIST']

Quantifying Accuracy of Metal Additive Processes Through a Standardized Test Artifact

Conference paper

https://repositories.lib.utexas.edu//bitstreams/db1ab32c-1272-4423-bad5-bf6319715aea/download

University of Texas at Austin

Two limitations of AM processes when compared to CNC subtractive processes are reduced dimensional accuracy and rougher surface finish. Accuracy and surface finish of metal additive processes, such as DMLS or SLM, are generally much looser than precision turning or grinding processes. Because of this, it is important to have an understanding of an AM machine’s capabilities—the designer must be satisfied with the tolerances and finishes possible, or additional post-processing must be added. One way to examine the capabilities of an AM process is by printing and measuring test artifacts. This paper examines a test artifact proposed by NIST that is intended to demonstrate many different capabilities and types of accuracy. Three identical builds are printed on a Concept Laser metal additive machine and measured. The capabilities of the machine are quantified and discussed, along with additional recommendations for improving the test structure design and the measurement process.

null

['Limaye, Ameya', 'Rosen, David']

2020-02-14T15:51:43Z

9/1/04

Mechanical Engineering

null

['https://hdl.handle.net/2152/79989', 'http://dx.doi.org/10.26153/tsw/7014']

eng

2004 International Solid Freeform Fabrication Symposium

Open

Mask Projection Microstereolithography

Quantifying Dimensional Accuracy of a Mask Projection Micro Stereolithography System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/63358a64-b94a-4d1e-8914-4ad79a421b47/download

null

Mask Projection Microstereolithography is capable for fabricating true three-dimensional microparts and hence, holds promise as a potential micro-fabrication process for micro-machine components. In this paper, the Mask Projection Micro-Stereolithography (MPµSLA) system developed at the Rapid Prototyping and Manufacturing Institute at Georgia Institute of Technology is presented. The dimensional accuracy of the system is improved by reducing its process planning errors. To this effect, the MPµSLA process is mathematically modeled. In this paper, the irradiance received by the resin surface is modeled as a function of the imaging system parameters and the pattern displayed on the dynamic mask. The resin used in the system is characterized to experimentally determine its working curve. This work enables us to compute the dimensions of a single layer cured using our system. The analytical model is validated by curing test layers on the system. The model computes layer dimensions within 5% error.

null

['Park, Sang-in', 'Rosen, David W.']

2021-10-21T16:52:26Z

2015

Mechanical Engineering

null

https://hdl.handle.net/2152/89403

eng

2015 International Solid Freeform Fabrication Symposium

Open

['as-fabricated voxel modeling', 'mechanical property degradation', 'material extrusion']

Quantifying Mechanical Property Degradation of Cellular Material Using As-Fabricated Voxel Modeling for the Material Extrusion Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/7877551c-9867-4f79-83db-07c1eef4af37/download

University of Texas at Austin

When fabricating cellular material using the material extrusion process, manufacturing errors arise due to approximation of geometries during slicing and tool-path generation, as well as the finite filament size. Moreover, since a cellular material generally consists of a large number of structural elements such as struts and plates, it has large bounding surfaces to be approximated during the AM process, which can increase manufacturing error. The errors degrade the mechanical properties of a fabricated cellular material. In this paper, an as-fabricated voxel modeling approach is proposed to quantify mechanical property degradation. An additively manufactured strut is modeled using voxels based on material extrusion and its effective structural characteristics such as a cross-sectional area and the second moment of area are evaluated. The property degradation is assessed by comparing mechanical properties from tensile tests and performing discrete homogenization with obtained structural characteristics.

null

['Sinha, Swapnil', 'Meisel, Nicholas A.']

2021-11-11T15:43:56Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90225', 'http://dx.doi.org/10.26153/tsw/17146']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['in-situ embedding', 'embedding orientation', 'flexural property', 'additive manufacturing']

Quantifying the Effect of Embedded Component Orientation on Flexural Properties in Additively Manufactured Structures

Conference paper

https://repositories.lib.utexas.edu//bitstreams/3cb8e44f-2393-4c5b-bd46-5994761713ae/download

University of Texas at Austin

In-situ embedding with Additive Manufacturing (AM) enables a user to insert functional components in a part by pausing the print, inserting the component into a specially designed cavity, and then resuming the print. This introduces the capability to merge the reliable functionality of external parts into AM structures, allowing multifunctional products to be manufactured in a single build. Previous research has shown that process interruption introduces weaknesses at the paused layer, and the presence of an embedding cavity further reduces the maximum tensile strength of the part. The research presented in this paper expands this understanding by investigating the impact of the process and design considerations for embedding on the strength of the material extrusion parts. A cuboidal geometry is embedded with different orientations with a flush surface at the paused layer, and tested for maximum bending strength. The findings help to further design guidelines for embedding with material extrusion AM.

null

['Moges, Tesfaye', 'Yan, Wentao', 'Lin, Stephen', 'Ameta, Gaurav', 'Fox, Jason', 'Witherell, Paul']

2021-11-15T21:07:32Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90272', 'http://dx.doi.org/10.26153/tsw/17193']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'powder bed fusion', 'uncertainty quantification', 'melt pool model', 'design of experiments']

Quantifying Uncertainty in Laser Powder Bed Fusion Additive Manufacturing Models and Simulations

Conference paper

https://repositories.lib.utexas.edu//bitstreams/d944da48-668e-4752-96c5-39ce07d895d8/download

University of Texas at Austin

Various sources of uncertainty that can potentially cause variability in the product quality exist at different stages of the laser powder bed fusion (L-PBF) process. To implement computational models and simulations for quality control and process optimization, quantitative representation of their predictive accuracy is required. In this study, a methodology to estimate uncertainties in L-PBF models and simulations is presented. The sources of uncertainty, including those due to modeling assumptions, numerical approximation, input parameters, and measurement error, are discussed in detail and quantified for low and high-fidelity melt pool simulation models. A design of experiments (DOE) approach is leveraged to quantify uncertainty due to input parameters and investigate their effects on output quantities of interest (QoIs). The result of this work is essential for understanding the tradeoffs in model fidelity and guiding the selection of a model suitable for its intended purpose.

null

['Sojiphan, K.', 'Babu, S.S.', 'Yu, X.', 'Vogel, S.C.']

2021-10-05T19:29:53Z

2012

Mechanical Engineering

null

['https://hdl.handle.net/2152/88418', 'http://dx.doi.org/10.26153/tsw/15357']

eng

2012 International Solid Freeform Fabrication Symposium

Open

['very high power ultrasonic additive manufacturing', 'crystallographic texture', 'heat treatments', 'aluminum alloy']

Quantitative Evaluation of Crystallographic Texture in Aluminum Alloy Builds Fabricated by Very High Power Ultrasonic Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/564d0285-5b25-44be-8622-6a45ef235640/download

University of Texas at Austin

Very high power ultrasonic additive manufacturing (VHPUAM) has shown good bond quality over traditional ultrasonic consolidation processes. However, the stability of microstructure in bulk and interface regions is unknown. Our earlier research showed a large difference in grain growth kinetics between bulk and interface regions. Therefore, we have performed in-situ studies of crystallographic texture evolution using a neutron beam line, before, during, and after heat treatment at 343oC for 2 hours. Shear texture in the as-received condition was found to be stronger with higher vibration amplitudes. We also observed rapid reduction of rolling textures in the initial material and presence of shear textures even after heat treatment.

null

['Denton, Karl R.', 'Jacobs, Paul F.']

2018-09-27T19:56:13Z

1994

Mechanical Engineering

doi:10.15781/T26Q1T23T

http://hdl.handle.net/2152/68609

eng

1994 International Solid Freeform Fabrication Symposium

Open

['Rapid prototyping', '3D Printing', 'StereoLithography']

QuickCast™ & Rapid Tooling: A Case History at Ford Motor Company

Conference paper

https://repositories.lib.utexas.edu//bitstreams/29973e4f-4e50-49eb-aa3f-b0a8174a545c/download

null

['Büsching, J.', 'Koch, R.']

2021-11-08T22:28:03Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/90056', 'http://dx.doi.org/10.26153/tsw/16977']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['ramp-up-management', 'additive manufacturing', 'technology integration', 'business process', 'business infrastructure', 'OptiAMix']

Ramp-Up-Management in Additive Manufacturing – Technology Integration in Existing Business Processes

Conference paper

https://repositories.lib.utexas.edu//bitstreams/3e483d4d-edbf-4415-975d-9e27c5145693/download

University of Texas at Austin

In conventional manufacturing, ramp-up-management describes the planning and organization of the period between finished product development and the achievement of full production capacity for defined products. This classification has to be adapted and restructured by means of product independent and tool-free production in additive manufacturing. Therefore ramp-up-management already starts with decisions on the extent of the use of additive manufacturing, includes the building of technology-know-how as well as the technology integration into processes and infrastructure of the company and ends with the attainment of a sufficient process reliability for the AM-machine. This paper focuses on technology integration in processes and infrastructure, which is part of the German research project OptiAMix. In this project, new systems for process state analysis adapted to additive manufacturing and methods for the optimal integration of additive manufacturing are developed. Furthermore ways of using the synergies of existing infrastructures and new innovative production technologies are determined.

null

['Perez, Mireya A.', 'Ramos, Jorge', 'Espalin, David', 'Hossain, Mohammad S.', 'Wicker, Ryan B.']

2021-10-12T19:06:21Z

2013

Mechanical Engineering

null

['https://hdl.handle.net/2152/88723', 'http://dx.doi.org/10.26153/tsw/15657']

eng

2013 International Solid Freeform Fabrication Symposium

Open

['desktop additive manufacturing', 'additive manufacturing', '3D printing', 'ranking model']

Ranking Model for 3D Printing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/03fe05ac-6eaf-4609-adeb-1d90eab03fc8/download

University of Texas at Austin

The capabilities of desktop additive manufacturing (AM) machines were evaluated based on the ability to produce a standard component. This work also developed a model/method for evaluating and ranking AM technologies based on select criteria that can facilitate purchasing decisions. A standard part was adapted and printed on each machine, and evaluated in various ways to provide machine-specific input data for the model. The research highlights the differences between AM units and suggests a method by which to evaluate the differences. With the rapid proliferation of desktop additive manufacturing units, a quantitative ranking system was developed to rate these units so that the consumer, for example, can use this model to assist with decision making during purchase. Although the focus of the work was on desktop systems, the approach can be applied across other AM technologies.

null

['Brooks, W.', 'Sutcliffe, C.', 'Cantwell, W.', 'Todd, J.', 'Mines, R.']

2020-02-21T15:06:42Z

8/3/05

Mechanical Engineering

null

['https://hdl.handle.net/2152/80060', 'http://dx.doi.org/10.26153/tsw/7082']

eng

2005 International Solid Freeform Fabrication Symposium

Open

Selective Laser Melting

Rapid Design and Manufacture of Ultralight Cellular Materials

Conference paper

https://repositories.lib.utexas.edu//bitstreams/82d18056-4877-4e1e-934f-f855538623b0/download

null

This paper details the design, manufacture and testing of regular metallic lattice structures with unit cell sizes in the range 0.8mm to 5mm and truss elements of 100-500 µm in diameter [1]. The structures were manufactured using Selective Laser Melting (SLM) technology from 316L stainless steel. Compression tests have shown yield loadings of over 3.5kN despite being only 18mm by 18mm by 10mm in height, the results are favourably comparable to current commercially available metallic foams. Software has been developed that creates slice files without the use of CAD software or STL files and is capable of producing lattices within a volume defined by a STL file.

null

['Kadakia, Samit R.', 'Novac, Andrei S.', 'Roosendaal, Mark D. Van', 'Thomas, Charles L.', 'Smith, Norman T.', 'Balogh, Matthew']

2018-11-30T15:04:55Z

1997

Mechanical Engineering

doi:10.15781/T23N2108K

http://hdl.handle.net/2152/70592

eng

1997 International Solid Freeform Fabrication Symposium

Open

['RP technique', 'Rapid Prototyping']

Rapid Fabrication of Disposable Fixtures for Correct Assembly of Split Build Rapid Prototyped Parts

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b5cc8a93-874b-4fbc-97a7-a43d5c59f196/download

null

The size of part that can be produced in a single build on any ofthe commercially available Rapid Prototyping systems is limited by the size ofthe particular machine's build envelope. Parts which exceed the dimensions ofthe build envelope are split into sections that fit the machine's envelope and these sections are fabricated separately. Assembly ofthe sections into an accurate three dimensional object often requires the creation of a fixture. This fixture ensures correct positional and angular orientation ofthe sections during assembly. This paper discusses the fabrication ofsuch fixtures using Shapemaker II, a Solid Freeform Fabrication process developed at the University ofUtah. Using Shapemaker II, large fixtures (4 ft. by 8 ft. or even larger) can be created in just a few hours. While the fixture is reusable, given the low cost ofthe fixture, it can be considered a throwaway item.

null

['Yang, D. Y.', 'Kim, H. C.', 'Lee, S. H.', 'Ahn, D. G.', 'Park, S. K.']

2020-02-20T19:52:42Z

8/29/05

Mechanical Engineering

null

https://hdl.handle.net/2152/80045

eng

2005 International Solid Freeform Fabrication Symposium

Open

['Rapid prototyping', 'Large-sized solid shape', 'VLM-ST process', 'MHC process']

Rapid Fabrication of Large-sized Solid Shape using Variable Lamination Manufacturing and Multi-functional Hotwire Cutting System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/658ad111-687f-410e-af99-53c58584f3d5/download

null

Rapid prototyping (RP) technologies have been widely used to reduce the lead-time and development cost of new products. The VLM-ST process has been developed to overcome the currently developed RP technologies such as a large building time, a high building cost, an additional post-processing and a large apparatus cost. However, the VLM-ST process has the limitation of fabricated model size (VLM300: 297×210 mm, VLM400: 420×297 mm) and the limitation of slope angle when the large-sized model more than 600 × 600 × 600 mm or axisymmetric shape is fabricated. The objective of this paper is to develop a multi-functional hotwire cutting system (MHC) using EPS-foam block or sheet as the working material in order to fabricate a large-sized shape more than 600 × 600 × 600 mm. Because the MHC apparatus employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turn-table, it allows the easy fabrication of various 3D shapes, such as (1) an axisymmetric shape or a sweeping cross-sectioned pillar shape using the hot-strip in the form of sweeping surface and EPS foam block on the turn-table, (2) a polyhedral complex shape using the hotwire and EPS foam block on the turn-table, and (3) a ruled surface approximated freeform shape using the hotwire and EPS foam sheet. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated by the apparatus.

null

['Kobliska, John', 'Ostojic, Petar', 'Cheng, Xudong', 'Zhang, Xugang', 'Choi, Honseok', 'Yang, Yong', 'Li, Xiaochun']

2020-02-24T15:31:09Z

8/26/05

Mechanical Engineering

null

['https://hdl.handle.net/2152/80083', 'http://dx.doi.org/10.26153/tsw/7104']

eng

2005 International Solid Freeform Fabrication Symposium

Open

thin film thermocouples

Rapid Fabrication of Smart Tooling with Embedded Sensors by Casting in Molds Made by Three Dimensional Printing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/12b6c17a-4401-425a-817c-20ac87a5317c/download

null

This paper is to investigate the feasibility of constructing “smart tooling” by embedding thin film sensors, specifically, thin film thermocouples (TFTC) in castings made by molds formed by 3 Dimensional Printing (3DP). This study investigates whether thin film sensors can effectively be cast into larger metal structures and if the sensors survive the casting process. The investigation includes making 3DP molds to produce cast lap joint test bars of aluminum A356 and electroplated nickel to characterize by mechanical testing to find the best process conditions to maximize bond strength between the embedded thin film sensors and the cast material. Lastly molds were made and embedded sensors were placed inside the mold for casting. Some of the embedded sensors survived the casting process. In-situ monitoring of casting process with the embedded sensors was accomplished.

null

['Zhang, Wei', 'Leu, Ming C.', 'Ji, Zhiming', 'Yan, Yongnian']

2019-02-19T20:02:45Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73441', 'http://dx.doi.org/10.26153/tsw/593']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['Solid Freeform Fabrication', 'Rapid Prototyping']

Rapid Freezing Prototyping with Water

Conference paper

https://repositories.lib.utexas.edu//bitstreams/834813bb-4001-4413-b53b-bcf0e033dbe7/download

null

Rapid Freezing Prototyping (RFP) with water is a novel solid freeform fabrication technique that can generate three-dimensional ice objects by depositing and rapidly freezing water layer by layer. The support where necessary is made of brine whose. freezing point is lower than. pure water. After building the part, the support can be removed by utilizing the melting temperature difference between brine and water. Preliminary experiments have shown that the ice patterns produced by this technique can be used for design visualization and silicone molding. This paper will present the concept and some experimental results of the RFP process as well as potential applications.

null

['House, M. A.', 'Whitney, E. J.', 'Krantz, D. G.', 'Arcella, F. G.']

2018-11-14T16:55:49Z

1996

Mechanical Engineering

doi:10.15781/T20Z71G7F

http://hdl.handle.net/2152/70240

eng

1996 International Solid Freeform Fabrication Symposium

Open

['titanium metals', 'Rapid prototyping', 'LaserCast']

Rapid Laser Forming of Titanium Near Shape Articles: LaserCast

Conference paper

https://repositories.lib.utexas.edu//bitstreams/fec1a1f0-b938-4726-99f7-e17021bfc3fb/download

null

An ongoing collaborative program sponsored by the DoD Advanced Research Projects Agency (DARPA) and the Office ofNaval Research (ONR) continues to show promising results in the development of a new laser based manufacturing process. The program's goals are to develop and demonstrate a laser based, rapid manufacturing system (LaserCastTM) for titanium and its alloys. Economical precursor powders are being laser formed into integral, 100% dense, nearshape articles by sequentially fusing multiple metal-powder layers in a controlled environment. A CO2 continuous wave (CW) high energy laser has been used to form commercially pure (CP) titanium, Ti-6AI-4V, and Ti-5AI-2.5Sn in varied geometries from I-inch square bars to a 4-inch diameter (I-inch wall ) cylinder. Materials characterization tests, revealing excellent chemistry control and mechanical properties, are presented. Large near-shape structures may be formed directly from metal powders, without using molds or dies, by direct download and postprocessing from a Computer Aided Design (CAD) database. Economic projections indicate significant reductions in manufacturing costs and "time to market" production cycles when the LaserCast process is used instead of conventional casting and forging processes.

null

['Bingham, G. A.', 'Crookston, J . J.', 'Hague, R. J. M.', 'Long, A. C.']

2020-02-27T19:32:55Z

9/14/06

Mechanical Engineering

null

['https://hdl.handle.net/2152/80095', 'http://dx.doi.org/10.26153/tsw/7116']

eng

2006 International Solid Freeform Fabrication Symposium

Open

Rapid Manufacturing

Rapid Manufactured Textiles

Conference paper

https://repositories.lib.utexas.edu//bitstreams/c22a25ff-46da-477a-b09d-ab3ede4b5ab0/download

null

Rapid Manufacturing (RM) is increasingly becoming a viable manufacturing process due to dramatic advantages that are achievable in the area of design complexity. Through the exploration of the design freedom, this paper introduces the concept of manufacturing textiles for potential smart and high performance textile applications. This paper discusses the current limitations associated with the manufacture of textiles through RM and presents a novel methodology for the generation of 3D conformal RM textile articles. The paper concludes that through RM it is entirely possible to manufacture a structure that incorporates drape and free movement properties directly comparable to conventional textiles.

null

['Frank, Matthew C.', 'Hunt, Christopher V.', 'Anderson, Donald D.', 'McKinley, Todd O.', 'Brown, Thomas D.']

2021-09-28T17:58:32Z

9/10/08

Mechanical Engineering

null

['https://hdl.handle.net/2152/88138', 'http://dx.doi.org/10.26153/tsw/15079']

eng

2008 International Solid Freeform Fabrication Symposium

Open

['rapid manufacturing', 'bone replacement', 'Subtractive Rapid Prototying']

Rapid Manufacturing in Biomedical Materials: Using Subtractive Rapid Prototyping for Bone Replacement

Conference paper

https://repositories.lib.utexas.edu//bitstreams/ae7db5b6-da94-4bd8-aeaa-3da918723930/download

University of Texas at Austin

This paper presents methods for the rapid manufacturing of replacement bone fragments using a Subtractive Rapid Prototyping process called CNC-RP. The geometry of segmental defects in bone, resulting from traumatic injury or cancerous tumor resection, can be reverse-engineered working from medical images (such as CT scans), and then accurate defect fillers can be automatically generated in advanced synthetic biomaterials and other bioactive/biocompatible materials. The research provides evidence that suitable bone geometries can be created using subtractive RP from a variety of materials including Trabecular Metal® (porous tantalum), polymers, ceramics, and actual bone allografts. The research has implications in the orthopaedic treatment of segmental bone defects, as custom prototyped bone fillers should aid in bone growth and improve recovery.

null

['Evans, R. S.', 'Bourell, D. L.', 'Beaman, J. J.', 'Campbell, M. I.']

2020-02-13T19:16:58Z

8/4/04

Mechanical Engineering

null

['https://hdl.handle.net/2152/79963', 'http://dx.doi.org/10.26153/tsw/6988']

eng

2004 International Solid Freeform Fabrication Symposium

Open

rapid manufacturing

Rapid Manufacturing of Silicon Carbide Composites

Conference paper

https://repositories.lib.utexas.edu//bitstreams/48af05fc-53dd-45c8-afb8-7b7220b776be/download

null

From the earliest days of SFF technology development, a viable technique for the direct manufacture of fully-functional parts has been a major technology goal. While direct metal methods have been demonstrated for a variety of metals including aluminum, steel and titanium, they have not reached wide commercial application due to processing speed, final material properties and surface finish. In this paper the development of an SLS-based rapid manufacturing (RM) platform is reviewed. The core of this platform is a thermosetting binder system for preform parts in contrast to the thermoplastic materials currently available for SLS. The preforms may include metal and/or ceramic powders. A variety of fully functional parts can be prepared from different combinations of materials and post processing steps including binder pyrolysis, free-standing alloy infiltration, room temperature polymer infiltration and machining. The main issues of these steps are reviewed followed by a discussion about the support of RM. This paper is an intermediate report additional materials, applications, process models and product design strategies will be incorporated into the project in the next year.

null

['Hague, Richard', 'Dickens, Phill']

2019-12-05T16:59:44Z

2004

Mechanical Engineering

null

['https://hdl.handle.net/2152/78647', 'http://dx.doi.org/10.26153/tsw/5703']

eng

2004 International Solid Freeform Fabrication Symposium

Open

Manufacturing

Rapid Manufacturing Research Group

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a64e1181-e572-4400-87b6-e5a29198249f/download

null

Rapid Product Development and manufacture is a major focus for companies wanting to compete in the more open Global Marketplace. This has created considerable interest in techniques and technologies that help companies introduce new products more quickly, at lower cost and with greater flexibility. Computer Aided Design (CAD) and the introduction, in the late 1980s, of a group of technologies known as 'Rapid Prototyping' have greatly helped this. It is now possible to design and manufacture objects within a few hours. The next stage is to use these layermanufacturing technologies to manufacture saleable end-use items. However, few companies have invested in the technology, but many are very interested in investigating their use. The research portfolio of the RMRG is directed at providing the future technologies industry will require, and, through the Consortium, is providing a route that allows partners, and others, to gain the required knowledge and expertise concerning the technologies and their use.

null

['Larsson, Morgan', 'Lindhe, Ulf', 'Harrysson, Ola']

2019-11-21T17:58:23Z

2003

Mechanical Engineering

null

['https://hdl.handle.net/2152/78547', 'http://dx.doi.org/10.26153/tsw/5603']

eng

2003 International Solid Freeform Fabrication Symposium

Open

Rapid Manufacturing

Rapid Manufacturing with Electron Beam Melting (EBM) - A Manufacturing Revolution?

Conference paper

https://repositories.lib.utexas.edu//bitstreams/95ae95bc-b9fe-4e88-abdf-156d5c478ff3/download

null

The Electron Beam Melting technology is the result of intensive research and development and has a wide array of applications within areas such as Rapid Prototyping, Rapid Manufacturing, Tooling and Biomedical Engineering. The technology combines first-class material properties with high build speeds. The presentation will provide a basic understanding of the technology, technical status, applications and ongoing R&D.

null

['Menon, Unny', 'Koch, Martin']

2018-04-16T17:21:20Z

1991

Mechanical Engineering

doi:10.15781/T2DJ5904V

http://hdl.handle.net/2152/64310

eng

1991 International Solid Freeform Fabrication Symposium

Open

['Industrial Engineering Department', 'Design and Manufacturing Processes', 'rapid prototyping']

Rapid Prototype for Foundry Tool Making: Curriculum and Industrial Projects

Conference paper

https://repositories.lib.utexas.edu//bitstreams/1eb99c52-5571-4590-b51f-41acd2572bff/download

null

This paper presents the evolution of an experimental .courseat Cal Poly which applies rapid prototyping techniques, enabling a concurrent engineering approach to product development. This is applied within our manufacturillgenvironmentof foundry and machining processes. It focuses upon the.mainprobletnof rapid tooling for these processes. A contemporary problenlprovided by industry is used as the vehicle for illustrating rapidprototyping techniques within a concurrent engineering context.

null

['de Beer, D.J.', 'Barnard, L.J.', 'Booysen, G.J.']

2019-10-22T17:42:47Z

2002

Mechanical Engineering

null

['https://hdl.handle.net/2152/76324', 'http://dx.doi.org/10.26153/tsw/3413']

eng

2002 International Solid Freeform Fabrication Symposium

Open

Visualisation

Rapid Prototyping (through SLS) as Visualisation Aids for Architectural Use

Conference paper

https://repositories.lib.utexas.edu//bitstreams/784e83b7-9665-4acc-aec9-19127f48e45e/download

null

The Cambridge International Dictionary of English, explains the word "Design" as a "pattern used to decorate something". Whilst this very narrow-minded definition can spark a debate on the meaning of design, it does however imply, that something has to made or manufactured, following a process-chain which started with an idea, followed by the design, and finally, the new product. As Functional Design is closely linked to inter alia manufacturing and building, Designers' freedom to express themselves, are often limited by the capabilities of craftsmen who have to give physical substance to Designer's ideas. The recently completed Manufacturing and Materials national FORESIGHT report [1] from the Department of Arts, Culture, Science and Technology (DACST) of the South African Government shows that manufacturers wishing to compete internationally should focus on integrated product, process and production system design, to speed up production time. This is all encapsulated in Concurrent Engineering, where design and approval are configured into a parallel, iterative process. Whilst it is not only dependent of technologies, technology and enabling tools such as Rapid Prototyping, applied in an integrated process, are crucial in the successful application of Concurrent Engineering. In the past a series of technologies, e.g. CAD, CAM and NC manufacturing was identified to solve these problems. Rapid Prototyping, Solid Freeform Fabrication or Generative Manufacturing - which are all synonyms for new methods of building physical parts directly from CAD data - represent the latest trends in manufacturing technology. However, all these techniques represent only a technological view on how product development can meet the tremendous challenges of the future. In fact, not merely the use of a single technology provides better products faster for the market, but the integration of a large number of technologies and methodologies. Therefore, aspects of information processing, cost, quality and time management, team work, organisational issues and many other enabling technologies like data highways, multi-media or distributed databases have to be taken into account as well. Rapid Prototyping is being used more and more as a key enabling technology in reducing the time to market for new products, by identifying possible design flaws prior to tooling and manufacturing, and is providing the common focus for multidisciplinary groups, around which to resolve design and development questions. Barkan and Iansti present RP as a means of rapid learning at every stage of the design process. Adopting this view on the whole of the development process, one comes to the conclusion that the use of RP to enable Rapid Product Development, is a fundamental challenge that must be addressed by all manufacturers to remain competitive in today's global market place. 35 In defining manufacturing, one tends to think about plastic products, casting, tooling concerned, and mass production. Whilst this represents the latest trends in manufacturing, one of the oldest methods of manufacturing however, is the conversion of basic raw materials into accommodation, shelters, etc. In adopting Rapid Prototyping and related technologies into the built and architecture environment, numerous new opportunities open up. The paper describes a fresh approach into an age-old industry.

null

['Chiang, J.', 'Lehmicke, M.', 'Dcosta, D.', 'Xu, X.', 'Lin, F.', 'Sun, W.']

2019-10-18T16:50:47Z

2001

Mechanical Engineering

null

['https://hdl.handle.net/2152/76258', 'http://dx.doi.org/10.26153/tsw/3347']

eng

2001 International Solid Freeform Fabrication Symposium

Open

Assisted

Rapid Prototyping Assisted Design and Development of Inter-Vertebral Implants

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f3ed627e-44d7-47a7-bae5-4cddbc70561c/download

null

This paper presents a case study of applying rapid prototyping in assisting in the design and development of inter-vertebral implants for spine fusions. The major process of design and implant development, its biological and mechanical requirements, the approach for developing a 3D reconstructive vertebral anatomy model, the inter-vertebral implant CAD model, and the integration with a finite element analysis for the implant's structural analysis are presented. The process of 3D Printing of the vertebral anatomy and the inter-vertebral implant is described. The application of the prototyping model in assisting in the inter-vertebral anatomic fitting, in guiding the implant's geometric design, in helping with the virtual surgical planning, and in understanding the implant's mechanical properties and structural stability are discussed.

null

['Roberts, Floyd', 'Lomshek, David', 'Brower, William E.']

2018-04-19T18:20:58Z

1992

Mechanical Engineering

doi:10.15781/T2MK65R8K

http://hdl.handle.net/2152/64404

eng

1992 International Solid Freeform Fabrication Symposium

Open

['CAD designs', 'rapid prototyping', 'in-flight rapid prototyping']

Rapid Prototyping at Zero Gravity for In-Flight Repairs and Fabrication on Space Station Freedom

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b78be0b8-883a-4810-876d-238f11e34a30/download

null

The ability to perform in-flight rapid prototyping would be of great benefit to NASA in two ways. First, repair parts could be fabricated from CAD designs beamed up from earth based laboratories which might allow a failed experiment to proceed. The mission specialists themselves, under the creative influence of space flight, might design a new part or tool and fabricate it on board in a matter of hours. Second, with metal casting and ceramic sintering facilities on board, rapid prototyping would allow manufacturing in space. This paper presents some test criteria for evaluating two of the rapid prototyping techniques, stereolithography and fused deposition, in microgravity conditions. Effects of the variation of head speed and strip width for the fused deposition process on the resulting mechanical properties are presented. The mechanical strength of the polyamide test bars increased with both increasing head speed and strip width. Increasing head speed would be desirable in microgravity applications.

null

['Wang, Jianguo', 'Wong, Y.S.', 'Fuh, Jerry', 'Loh, H.T.', 'Du, ZhaoHui', 'Hong, GuoDong', 'Yan, YongNian']

2019-02-19T20:17:49Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73444', 'http://dx.doi.org/10.26153/tsw/596']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['CAD', 'CMM']

Rapid Prototyping Based on 2D Photographic Images

Conference paper

https://repositories.lib.utexas.edu//bitstreams/525e0d9f-51ca-4697-a78b-1916445165cf/download

null

Generally it is difficult to get a 3D model from its 2D images. However, if the object is symmetric and its photograph is taken in appropriate perspective, then it is possible to extract pertinent 3D information from its 2D images. In this paper, a reverse engineering method to derive the 3D surface model from 2D photographs is introduced. Through a case study, the entire process from photo taking to 3D model making and subsequent rapid prototyping of a model car is introduced. The techniques and related problems of reverse engineering and rapid prototyping are discussed and the future research direction is proposed.

null

['Jones, K. G.', 'Campbell, R. I.']

2018-12-06T21:57:43Z

1997

Mechanical Engineering

doi:10.15781/T2P55F32K

http://hdl.handle.net/2152/71433

eng

1997 International Solid Freeform Fabrication Symposium

Open

['Rapid Prototyping', 'RPDSS']

Rapid Prototyping Decision Support System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a1b859ac-2138-4f30-b461-dffbda93aded/download

null

An application has been produced to rate Rapid Prototyping system suitability based on designer requirements. The software is part of a project to produce a comprehensive Design For Rapid Prototyping (DFRP) methodology. Using a combination of database searches and user-defined weighted. rating, the system uses various design requirements to make qualitative suitability decisions. MS Visual Basic has been used to implement a user-interface to manipulate an MS Access database. Proposed features include system validation achieved by designers' feedback on prototype performance. This will help to remove the false expectations sometimes associated with RP and will ultimately promote its wider usage.

null

['Prasad, K. Siva', 'Rathakrishnan, E.', 'Dhande, Sanjay G.']

2019-11-21T17:42:41Z

2003

Mechanical Engineering

null

['https://hdl.handle.net/2152/78541', 'http://dx.doi.org/10.26153/tsw/5597']

eng

2003 International Solid Freeform Fabrication Symposium

Open

Aerospace

Rapid Prototyping for Aerospace Launch Vehicles

Conference paper

https://repositories.lib.utexas.edu//bitstreams/aca7045b-a747-409e-8ad2-72aab062a210/download

null

Initial studies of the aerodynamic characteristics of proposed launch vehicles can be made more accurately if lower cost, high-fidelity aerodynamic models are available for wind tunnel testing early in design phase. Rapid Prototyping (RP) is an emerging key technology for producing accurate parts directly from CAD models quickly, with little need of human intervention. Use of RP models was studied at the NASA Marshall Space Flight Center (MSFC). It was concluded that RP methods and materials can be used only for preliminary design studies and limited configurations because of the RP material properties that allow bending of models under higher loading conditions. The reported results and analysis were based on wind tunnel balances. These balances give total load on the body. Thus, there is a need for studying the pressure distribution, the wave pattern and the system behavior under high-speed conditions. In order to study the above goals, a blunt nose cone of a launch vehicle/ missile was tested which was made using the solid based RP method FDM, with a Mach number of 2.0. It is concluded that RP models can take the load at the Mach number 2.0 and also can capture the pressure distribution and wave pattern.

null

['Geng, L.', 'Wong, Y.S.', 'Hutmacher, D.W.', 'Feng, W.', 'Loh, H.T.', 'Fuh, J.Y.H.']

2019-11-21T17:56:34Z

2003

Mechanical Engineering

null

['https://hdl.handle.net/2152/78546', 'http://dx.doi.org/10.26153/tsw/5602']

eng

2003 International Solid Freeform Fabrication Symposium

Open

Scaffolds

Rapid Prototyping of 3D Scaffolds for Tissue Engineering Using a Four-Axis Multiple-Dispenser Robotic System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/3a243bff-bc47-4656-ba0d-f87b3db1894e/download

null

A desktop rapid prototyping (RP) system has been developed to fabricate scaffolds for tissue engineering (TE) applications. The system is a computer-controlled four-axis machine with a multiple-dispenser head. This paper presents the scaffold fabrication process to build free-form scaffolds from relevant features extracted from given CT-scan images for TE applications. This involves obtaining the required geometric data for the scaffold in the form of a solid model from CT-scan images. The extracted scaffold model is then sliced into consecutive two-dimensional (2D) layers to generate appropriately formatted data for the desktop RP system to fabricate the scaffolds. The basic material processing involves the sequential dispensing of two or more materials to form a strand. The four-axis system enables strands to be laid in a different direction at each layer to form suitable interlacing 3D free-form scaffold structures. The multipledispenser head also allows the introduction of living cells and additional materials during the scaffold building. The building of the scaffolds with the desktop RP system is described based on the sequential dispensing of chitosan dissolved in acetic acid and sodium hydroxide solution. Neutralization of the acetic acid by the sodium hydroxide results in a precipitate to form a gellike chitosan strand.

null

['Kumar, Ranjeet', 'Kapil, Sajan', 'Negi, Seema', 'Gehlot, Nihal', 'Gopalakrishna, Suhas Hurli', 'Karunakaran, K.P.']

2021-11-04T18:05:31Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/89991', 'http://dx.doi.org/10.26153/16912']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['rapid prototying', 'expanded polystyrene', 'evaporative pattern casting']

Rapid Prototyping of EPS Pattern for Complicated Casting

Conference paper

https://repositories.lib.utexas.edu//bitstreams/c9c33481-6a14-414d-aa88-2c3868e1a4f9/download

University of Texas at Austin

In Rapid Prototyping (RP) process the 3D object is approximated into several 2D slices. All these slices are of a uniform thickness hence called uniform slicing of zeroth order approximation. Such a system always suffers with the staircase defects. Very thin slices have to be used to minimize these defects, which increase the production time. In this work, a RP system called Segmented Object Manufacturing (SOM) is used to produce the Expanded Polystyrene (EPS) pattern, which uses adaptive slicing with higher order approximation. This system uses the concept of visible slicing in which a complicated object is produced by converting it into the accessible (visible) segments. This is a hybrid system for producing EPS patterns which utilizes the advantages from subtractive and additive processes. These EPS patterns found their application in Evaporative Pattern Casting (EPC). EPS bracket is produced by SOM machine to prove the capability of the system.

null

['Nakagawa, Takeo', 'Noguchi, Hiroyuki']

2018-11-09T16:34:16Z

1996

Mechanical Engineering

doi:10.15781/T2P844F9C

http://hdl.handle.net/2152/69933

eng

1996 International Solid Freeform Fabrication Symposium

Open

['CAD', 'R/P model', 'forming process']

Rapid Prototyping of Fine Ceramics: Slurry Casting Using Silicon Rubber Mold

Conference paper

https://repositories.lib.utexas.edu//bitstreams/20ad7367-cde2-4f19-9bdb-7f019e80b389/download

null

['Kupp, Donald', 'Eifert, Harald', 'Greul, Matthias', 'Kunstner, Matthias']

2018-11-29T20:54:29Z

1997

Mechanical Engineering

doi:10.15781/T2VH5D39J

http://hdl.handle.net/2152/70343

eng

1997 International Solid Freeform Fabrication Symposium

Open

['3D CAD', 'rapid prototyping.']

Rapid Prototyping of Functional Metal and Ceramic Components By The Multiphase Jet Solidification (MJS) Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/636c4298-e40b-414d-ab6f-da0bdb5da6f3/download

null

The need to generate high-quality conceptual models ofmanufacturing components and limited application functional components has driven the development ofRapid Prototyping (RP) in the last fifteen years. Recently, however, it has become increasingly obvious that an RP system that can produce fully functional components in materials other than polymers would be beneficial. In order to fulfill the requirements for the direct production ofmetallic and ceramic components for functional testing and application, the development ofnew processes and materials are key development areas at the Fraunhofer Institute for Applied Materials Research (IFAM) and the Fraunhofer Resource Center-Delaware (FRC-DE). For the free-form fabrication of ceramic and metal parts, the Multiphase Jet Solidification (MJS) process has been developed for producing metal and ceramic components. The MJS process extrudes metal and ceramic based binder systems (such as A120 3, SiC, stainless steel, and Ti), forming the desired component layer by layer. As in powder injection molding, after a part is formed by MJS, the binder phase is removed chemically or thermally and the remaining powder compact is sintered to final density. This paper presents the MJS technique and outlines a variety ofpotential applications.

null

['Maxwell, J.', 'Larsson, K.', 'Boman, M.']

2019-02-26T18:01:39Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73492', 'http://dx.doi.org/10.26153/tsw/642']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['laser chemical vapor deposition', 'primary fabrication tool']

Rapid Prototyping of Functional Three-Dimensional Microsolenoids and Electromagnets by High-Pressure Laser Chemical Vapor Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/732d3647-e62e-4985-ad53-983c4b082a4c/download

null

Three-dimensional laser chemical vapor deposition (3D-LCVD) is an emerging process which bridges the gap between various macro-scale rapid prototyping (RP) systems and microfabrication technologies. With the ability to deposit both metals and dielectrics 3D-LCVD may be used to prototype integrated electromechanical components from sub-micron to centimeter scales. This technological niche is increasingly important with the ever-decreasing size and sophistication of consumer and industrial products. The objective of this work was the development of functional microsolenoids and electromagnets, using 3D-LCVD as the primary fabrication tool. High-aspect-ratio microsolenoids have the potential to generate much greater magnetic-field densities than their thin-film counterparts,l and have many advantages when used as actuators in microelectromechanical systems (MEMS).2 3D-LCVD provides a means of fabricating such helical structures, with an ease unparalleled by any lithographic or rapid prototyping process.

null

['Wohlert, Martin', 'Bourell, David']

2018-11-09T15:14:43Z

1996

Mechanical Engineering

doi:10.15781/T2V11W54G

http://hdl.handle.net/2152/69924

eng

1996 International Solid Freeform Fabrication Symposium

Open

['RP Process', 'SLS', 'polymer debinding']

Rapid Prototyping of Mg/SiC Composites by a Combined SLS and Pressureless Infiltration Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/4b1adb24-433f-4e80-88b2-c1b18a9dcf4f/download

null

The expanding market for metal matrix composites (MMCs) presents a unique niche application for rapid prototyping I manufacturing. MMCs are well suited to RP for two reasons. First, these relatively new high performance materials are largely used in high cost, low production applications which are easily accommodated by RP techniques. Second, the hard and brittle ceramic reinforcement phases used in MMCs add cost and complexity to traditional production methods. Special tools or processes are required to machine these materials, and the cost and design limitations imposed by the production of a mold limit the competitiveness of casting [1,2]. In comparison, the additive nature of Selective Laser Sintering (SLS) avoids the problems associated with machining of the ceramic phase, and the wide range of geometries which can be produced ensures the versatility of the process.

null

['Lyons, Brett', 'Batalov, Marat', 'Mohanty, Pranavasu', 'Das, Suman']

2020-02-24T15:20:40Z

2005

Mechanical Engineering

null

['https://hdl.handle.net/2152/80081', 'http://dx.doi.org/10.26153/tsw/7102']

other

2005 International Solid Freeform Fabrication Symposium

Open

proton exchange membrane fuel cells

Rapid Prototyping of PEM Fuel Cell Bi-Polar Plates using 3D Printing and Thermal Spray Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f67847a2-f2a9-4593-a920-60d246f3425a/download

null

This article presents the results of exploratory research on novel methods for the fabrication of functional, metallic, gas flow, bi polar plates (BPP) for use in proton exchange membrane fuel cells (PEMFC). Low cost, high speed, additive manufacturing methods that combine 3D printing (3DP) and thermal spray (TS) technologies are described. Functional flow plates were manufactured by creating 3DP patterns and then depositing, and releasing, dense metals with TS methods. The new method yields dense metal plates, with interesting options for material choices and complex designs.

null

['Maxwell, James', 'Shah, Jubin', 'Webster, Terry', 'Mock, Jason']

2019-02-26T20:24:28Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73498', 'http://dx.doi.org/10.26153/tsw/648']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['3D-LCVD', 'alloys']

Rapid Prototyping of Titanium Nitride Using Three-Dimensional Laser Chemical Vapor Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/1d114032-a20b-4cf8-9206-9fd132852f05/download

null

Selective vapor deposition o/titanium nitride was realizedfrom titanium tetrakis-dimethylamide, Ti(N(CH3)2)4, at pressures up to 138 mbar. High-aspect-ratio needles up to mm long were grown at axial rates up to 10 pm/so The morphology and composition o/thefibers will be described. The temperature rise during transient growth was apparent in the grain size o/the resulting needles. Severe mass-transport limitations were also observed due to the multiplicity o/precursor by-products. A primary application o/this workwill be the rapidprototyping o/highly-elastic, lightweightstructural elements and matrices.

null

['Ribeiro, A. F.', 'Norrish, John']

2018-11-14T17:04:20Z

1996

Mechanical Engineering

doi:10.15781/T2W95174M

http://hdl.handle.net/2152/70241

eng

1996 International Solid Freeform Fabrication Symposium

Open

['Rapid prototyping', 'CAD', '3D solid component']

Rapid Prototyping Process Using Metal Directly

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a26c447c-8527-4aee-a9a6-630ee0355a5b/download

null

Rapid Prototyping emerged in the USA in the late 80's and it made the whole industry rethink their way of making prototypes. Several new different process have emerged since then and these vary in materials, times, prices, fInishing quality, etc. However, not many have achieved acceptable results with using 100% pure metal. Some heavy industry want prototypes made with metal in order to assess not only the shape of the prototype but also its hardness conditions and functionality of the component in real situations. This technique is still under development at several different places and although some research have been done recently the results are not yet as desired. In the last couple of years a Rapid Prototyping process involving direct deposition of metal had been under development (as a PhD research) at Cranfield University. The process entails the use of a Gas Metal Arc fusion welding robot which deposits successive layers of metal in such way that it forms a 3D solid component. A solid model is frrst drawn using a CAD system, then data indicating the kind of layers and dimension is incorporated and the solid is automatically sliced. This slicing routine also generates reports on the welding time and conditions for the production of the component and automatically generates the robot program. Depending on the complexity of the component, the time from drawing the component to being ready to press the robot start button to make the component can take less than a couple of hours. Several test components were produced with good characteristics and perfectly acceptable surface finishing. This paper describes the process and shows some samples.

null

['Dickens, P.M', 'Pridham, M.S', 'Cobb, R.C.', 'Gibson, I.', 'Dixon, G.']

2018-04-19T18:34:48Z

1992

Mechanical Engineering

doi:10.15781/T2ZW1990V

http://hdl.handle.net/2152/64409

eng

1992 International Solid Freeform Fabrication Symposium

Open

['3-D Welding', 'rapid prototyping', 'Department of Manufacturing Engineering and Operations Management', 'Laminated Object Manufacturing']

Rapid Prototyping Using 3-D Welding

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f3651875-456d-4d29-ade4-ecf5d30c5c96/download

null

Rapid prototyping systems are based, almost exclusively on polymer, or paper materials. The dimensions of the parts produced are limited by the volume of the processing area within the machine, and parts tend to warp or distort due to shrinkage and lack of support. Also the mechanical properties of the part are restricted to those of the processable materials and thus, in many cases, required 'engineering properties' cannot be obtained

null

['Dover, S J', 'Rennie, A E W', 'Bennett, G R']

2018-11-09T16:47:49Z

1996

Mechanical Engineering

doi:10.15781/T2902018X

http://hdl.handle.net/2152/69936

eng

1996 International Solid Freeform Fabrication Symposium

Open

['EDM', 'electrolyte', 'SFF']

Rapid Prototyping using Electrodeposition of Copper

Conference paper

https://repositories.lib.utexas.edu//bitstreams/8acf1be1-2f24-4d93-9609-2447582d1091/download

null

Injection mould cavities and EDM electrodes were produced from High Speed Selective Jet Electrodeposition (HSSJE). The performance ofthe electrodes in the EDM process and the surface finish ofthe tools produced were studied. Studies were made into optimising the HSSJE build process

null

Walters

2018-04-19T18:38:04Z

1992

Mechanical Engineering

doi:10.15781/T2KK94W0X

http://hdl.handle.net/2152/64412

eng

1992 International Solid Freeform Fabrication Symposium

Open

['FDM', 'Fused Deposition Modeling', 'manufacturing process']

Rapid Prototyping Using FDM: A Fast, Precise, Safe Technology

Conference paper

https://repositories.lib.utexas.edu//bitstreams/bcfe1fe5-0910-4533-b96e-16b172f73790/download

null

This paper outlines the use of FDM to speed product design and to streamline the manufacturing process. Time compression, the ability to quickly reduce the time it takes to get new products to market, has increased the pressure on all phases of the manufacturing process. Manufacturers must find and implement time saving systems without sacrificing quality.

null

['Soo, S.C.', 'Yu, K.M.']

2019-10-18T16:06:39Z

2001

Mechanical Engineering

null

['https://hdl.handle.net/2152/76247', 'http://dx.doi.org/10.26153/tsw/3336']

eng

2001 International Solid Freeform Fabrication Symposium

Open

Fractal

Rapid Prototyping using Fractal Geometry

Conference paper

https://repositories.lib.utexas.edu//bitstreams/2b3bc42a-1911-469e-9b29-df8497e6203d/download

null

The paper proposes a method for rapid prototyping (RP) fractal geometry represented objects. RP technology has made possible the physical fabrication of solid freeform objects. However, contemporary CAD/CAM/RP systems are developed for Euclidean geometry and are incapable of handling self-similar fractal objects (e.g. jewelry products). To address the problem, a Radial-Annular Tree (RAT) data structure is proposed to represent Iterated Function Systems (IFS) fractal curves. RP toolpaths can then be generated from the RAT data structure. Geometry modeled in the RAT data structure can also be combined with Euclidean geometry from traditional CAD systems to make aesthetic patterns for the jewelry industry.

null

['Campbell, R.I.', 'Dickens, P.M.']

2018-09-27T19:24:07Z

1994

Mechanical Engineering

doi:10.15781/T2M03ZG6J

http://hdl.handle.net/2152/68606

eng

1994 International Solid Freeform Fabrication Symposium

Open

['fastest developing manufacturing technologies', 'CAD', 'Photo polymerisation process development']

Rapid Prototyping: A Global View

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a103ff6c-435b-479e-afb5-9ec90d50b64f/download

null

Rapid prototyping technology is advancing at a tremendous rate. Much of this progress is due to research being conducted within academic institutions and industry throughout the world. The USA is leading the research community in this field but a significant contribution is coming from Europe, Japan and elsewhere. The primary aim of this paper is to give a worldwide overview of current research activity and initiatives. Hopefully, this will enable researchers to see where their own work fits into the global picture. If this leads to increased co-operation and a reduction in duplication of effort, then an even faster rate of advance should be attainable.

null

['Weaver, Timothy J.', 'Thomas, Julian A.', 'Atre, Sundar V.', 'German, Randall M.']

2019-02-26T16:41:09Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73484', 'http://dx.doi.org/10.26153/tsw/634']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['rapid prototyping', 'mechanical properties']

Rapid Steel Tooling Via Solid Freeform Fabrication

Conference paper

https://repositories.lib.utexas.edu//bitstreams/20643f19-204d-4b07-ad89-8f898b5b5297/download

null

With increasing part complexity and requirements for long production runs, tooling has become an expensive process that requires long lead times to manufacture. This lengthens the amount oftime from "art to part". Rapid tooling via stereolithography (SLA), filled epoxies, etc. have been stopgap measures to produce limited prototyping runs from (10 to 500 parts). This gives poor dimensional analysis and does not allow for limited production runs of 1000+ parts. The method ofproducing prototype tooling with a powdered metal process has been developed that produces tooling with a hardness greater than 35 HRC and total shrinkage less than 0.5%. This tooling process manufactures production ready tooling that will perform extended cycle runs (100,000+). Manufacturing ofthis tooling takes 1 to 2 weeks and will compare favorably with production grade steel tooling. Originals drawn in 3D CAD can be used to prototype the master that will allow for the production ofthe rapid metal tool set. process starts with a rapid prototyped model made by whatever process is desired or a machined master. For this paper a Sander's Model Maker II® rapid prototyping machine was used to fabricate the model. After the model ofthe tool set is made, a silicone rubber negative is cast around that model. After the silicone rubber model is made, a heated slurry ofmetal powders and polymers is poured into the mold to create the green tool set. The tool set is left to cool, and then removed from the silicone rubber mold. The tool set is then debound and sintered to produce a final tool set with properties approaching hardened tool steel.

null

['NOGUCHI, Hiroyuki', 'NAKAGAWA, Takeo']

2018-11-30T16:27:38Z

1997

Mechanical Engineering

doi:10.15781/T2KP7VB4N

http://hdl.handle.net/2152/70596

eng

1997 International Solid Freeform Fabrication Symposium

Open

['CAD', 'SLS']

Rapid Tooling by Powder Casting Transferred from RIP Model -Manufacturing Conditions Pursuing Zero Shrinkage

Conference paper

https://repositories.lib.utexas.edu//bitstreams/6646ec7e-fb28-43d3-b4f8-46eafd8ab755/download

null

High accuracy is being sought in the rapid manufacturing of long life metal dies and molds by transferring from layer laminated models. Powder casting serves as a promising rapid tooling method as it enables high density filling and thus controls dimensional shrinkage to a considerable extent during sintering and infutrating This study aims to study the relation between the tooling conditions and dimensional changes of powder casting and fmd the conditions at which dimensional changes are minimum. In the experiments performed, a golf ball model was chosen as an exampIe of a small mold and results show that dimensional changes can be controlled to below 0.1%, which will facilitate practical application. By subjecting the cast powder to vibrations after adding the binder to achieve higher density, and adding fme copper powder to a mixture of two different size stainless steel powders for dimensional adjustments, almost zero shrinkage control in rapid tool making was realized.

null

['Stucker, Brent', 'Malhotra, Muni', 'Qu, Xiuzhu', 'Hardro, Peter', 'Mohanty, Natalie']

2019-09-23T15:14:04Z

2000

Mechanical Engineering

null

['https://hdl.handle.net/2152/75931', 'http://dx.doi.org/10.26153/tsw/3030']

eng

2000 International Solid Freeform Fabrication Symposium

Open

Accuracy

RapidSteel Part Accuracy 133

Conference paper

https://repositories.lib.utexas.edu//bitstreams/af566322-8e8c-4c28-aa7f-38d4a85e014b/download

null

In order to assess the effect of various furnace processing parameters on RapidSteel part accuracy, a series of experiments were performed on linear dimensional changes during processing of RapidSteel 2.0 and LaserForm ST-100. An understanding of these dimensional changes is critical for building parts and tools which are capable of being used in high tolerance applications and for finish machining of near-net shapes to high tolerances. A unique part was designed for this study and is shown as Figure 1. This part has both internal and external measurable dimensions in the x, y and z axes. The smallest dimension in each direction is 0.3 inches and the largest dimension is 3.0 inches. This provides an order of magnitude difference between the smallest and largest dimensions.RapidSteel 2.0 (RS2) is a commercially available metal material from DTM Corporation. It is made by Selective Laser Sintering of stainless steel 316 powders with polymer binders followed by a binder burnout and sintering furnace run, and a second infiltration furnace run where a 90% Cu, 10% Sn bronze is infiltrated into the porous stainless steel structure. LaserForm ST-100 (ST-100) is the latest version of RapidSteel and is a stainless steel 420 material that is sintered and infiltrated in one furnace run. The significant difference between RS2 and ST-100 is that the ST-100 has a broader particle size range, with fine particles not being screened out. These fine particles allow the ST-100 material to be sintered at a lower temperature than the RS2 powder, which makes possible the single furnace run for sintering and infiltration. Benefits of ST-100 include that it is a magnetic material and can be fixtured using magnetic chucks and that the finer particles allow for greater feature definition, sharpness of corners and strength of green parts.

null

['Deppe, Gereon', 'Kaesberg, Martin', 'Koch, Rainer']

2021-11-08T22:30:30Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/90057', 'http://dx.doi.org/10.26153/tsw/16978']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'decision support', 'aerospace', 'spare parts', 'MADM', 'multi attribute decision making']

Rational Decision-Making for the Beneficial Application of Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/54662f10-6627-4f34-b180-9ae934814a73/download

University of Texas at Austin

Additive Manufacturing is a technology that offers a high potential for industrial companies. Nevertheless, companies lack experience with this new technology and face the problem to identify processes where a successful and beneficial application can be achieved. They have to be supported in this analysis with a decision support tool which is capable to compare different manufacturing or repair approaches in order to determine the optimal solution for the correspondent use case. This is not always driven solely by costs but can also be critically affected by further influencing factors. This is why the decision support takes into account also time and quality alongside the costs. For a time-critical spare part supply, for example within aerospace sector, they are substantial for taking a decision. The presented decision support features a multi-attribute decision-making approach for selecting the most appropriate process, either Additive Manufacturing, conventional technologies or an external procurement.

null

['Evans, R. Scott', 'Bourell, David L.', 'Beaman, Joseph J.', 'Campbell, Matthew I.']

2019-11-21T17:54:14Z

2003

Mechanical Engineering

null

['https://hdl.handle.net/2152/78545', 'http://dx.doi.org/10.26153/tsw/5601']

eng

2003 International Solid Freeform Fabrication Symposium

Open

Silicon Carbide

Reaction Bonded Silicon Carbide: SFF, Process Refinement and Applications

Conference paper

https://repositories.lib.utexas.edu//bitstreams/325431df-8772-436e-8c9d-186f8a41b3db/download

null

Reaction bonded silicon carbide (RBSiC) has a wide variety of industrial applications and a manufacturing process based on Selective Laser Sintering (SLS) has been demonstrated in previous research at the University of Texas. That study was directed toward semiconductor manufacturing applications and was based on prior indirect SLS methods. Several key research questions were addressed for three main manufacturing phases: preform SLS, binder burnout and reactive infiltration. The current research is focused on development of material systems and manufacturing capability and is directed toward a broader set of potential applications. Preform formation utilizes SiC powder of an appropriate average particle size mixed with a multicomponent binder. The preform or green part is then placed in a vacuum furnace to carbonize the binder. The details of the binder chemistry must support accurate SFF shapes and acceptable surface roughness, a strong green part and maintenance of the part shape during the first furnace operation. Finally, the physics and chemistry of the infiltration process, based on the microstructure of the initial green preform, determine the viability of the manufacturing process and the characteristics of the final composite material. The functionality of metal, polymer and ceramic matrix composites can support the growing SFF industry desire to move beyond functional prototyping and into manufacturing arenas. This project is being explored for more general application to matrix composite materials, especially highly functional systems tailored specifically for SLS. The goal is to establish the governing principles of binder function, carbonization and infiltration as well as to understand the interdependence of these phases in terms of manufacturing application. With this understanding new applications and special SLS composites can support the development of new products and a greater SFF manufacturing presence. This paper provides an introduction to the material, a look at basic rapid manufacturing trends, an overview of the previous work, a review of relevant RBSiC material science issues, and an outline of the current study.

null

['NARAHARA, Hiroyuki', 'TANAKA, Fumiki', 'KISHINAMI, Takeshi', 'IGARASHI, Satoru', 'SAITO, Katsumasa']

2018-12-07T17:18:55Z

1997

Mechanical Engineering

doi:10.15781/T2ZG6GT3V

http://hdl.handle.net/2152/71454

eng

1997 International Solid Freeform Fabrication Symposium

Open

['UV-laser beam', 'removal processing']

Reaction Heat Effect On Initial Linear Shrinkage of Sterelothigraphy Resins

Conference paper

https://repositories.lib.utexas.edu//bitstreams/1d333d08-cf18-42ae-b4af-86a53349b3b5/download

null

In the industrial use ofthe Stereolithography, the precision is always a problem. Basic phenomenon of the solidification shrink has not suffiCiently investigated This study aims at clarifying the initial linear shrinkage ofcured resin in a minute volume. Experimental equipment has been developed which measures the time history of the single strand in situ in a stereolithography machine. Analysis model about the time history of a minute volume linear shrinkage has been shown using with the measured shrinkage of a cured line segment. The relation between the time history ofthe linear shrinkage and the temperature was measured and the shrinkage in the minute volume after irradiation has been caused by the temperature variation

null

['Foerster, A.', 'Wildman, R.', 'Hague, R.', 'Tuck, C.']

2021-11-04T15:11:17Z

2017

Mechanical Engineering

null

['https://hdl.handle.net/2152/89983', 'http://dx.doi.org/10.26153/tsw/16904']

eng

2017 International Solid Freeform Fabrication Symposium

Open

['reactive inkjet printing', '3D silicone structures', 'elastomeric structures']

Reactive Inkjet Printing Approach Towards 3D Silicone Elastomeric Structures Fabrication

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f9132463-8efb-48a6-a61e-e607cd5ad0a3/download

University of Texas at Austin

Production of 3D silicone structures with tailored architectures has a wide number of applications including soft robotics and stretchable electronics. This work investigates a method based on a reactive inkjet printing approach to produce 3D silicone structures. Printing parameters including pressure and temperature for jetting SE1700 ink to produce silicone structures were optimised. Additives, silicone oil and vinyl terminated polydimethylsiloxane were added to the main SE1700 formula to evaluate mechanical properties of the final parts. Characterisation was performed to understand the change in a sample’s properties in relation to different formulations. Silicone structures with different porosities were printed and the mechanical properties were investigated. It has been demonstrated that 3D silicone structures can be produced using reactive inkjet printing approach. The presented method allowed tailoring of the mechanical properties of silicones without increasing the viscosity properties of the base material by adjusting the silicone formula and using different structures.

null

['Zhao, Changxuan', 'Jariwala, Amit S.', 'Rosen, David W.']

2021-10-28T15:17:24Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89661

eng

2016 International Solid Freeform Fabrication Symposium

Open

['photopoymerization', 'scanning points', 'real-time monitoring', 'exposure controlled projection lithography']

Real Time Monitoring of Exposure Controlled Projection Lithography with Time-Varying Scanning Points

Conference paper

https://repositories.lib.utexas.edu//bitstreams/46f26d68-cee5-45bb-bc15-5a0172f1793b/download

University of Texas at Austin

Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in which photopolymer resin is used to fabricate lens shaped features. During this process, a dynamic mask projects radiation patterns through a transparent substrate onto the photopolymer resin to grow features from the substrate surface. We present a novel method to monitor the photopolymerization process in real-time with higher spatial resolution in a plane perpendicular to the polymerization growth. A Spatial Light Modulator (SLM) was incorporated into our Interferometric Cure Monitoring (ICM) system, which periodically moves the positions of the scanning points onto the curing area to estimate the cured part height. This time-varying scanning strategy avoids interference caused by points too close to one another and enables higher spatial resolution than fixed scan patterns. This time-varying multi-point monitoring approach is experimentally validated to measure the cured part height and the lateral dimensions of the cured part at the substrate level.

null

['Bossett, Evan', 'Rivera, Lorna', 'Qiu, Dan', 'McCuiston, Ryan', 'Langrana, Noshir', 'Rangarajan, Shriram', 'Venkataraman, Natesan', 'Danforth, Stephen', 'Safari, Ahmad']

2019-02-19T17:46:41Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73434', 'http://dx.doi.org/10.26153/tsw/586']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['FDM', 'deposition']

Real Time Video Microscopy for the Fused Deposition Method

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a5ecc52b-aa43-42fb-8cd6-41083c0503de/download

null

Fused deposition is a layered manufacturing technology, which is being investigated for fabrication of functional parts. Defects and voids in the build process affect the quality andlevel of accuracy of components. These occur due to several factors, such as the.toolpath contours in a layer, material(s) deposited, and the environmental/conditions. For a functional part to be constructed, a perfect green part is critical. To further understand this process, a visualization of the deposition is needed. Therefore, we have developed a real-time. video microscopy system. The hardware has been constructed and mounted on theexistingliquifier.·Real time deposition·of layered manufacturing is being recorded. Three materials being investigated are: PZT, silicon nitride, and wax. The contrast in wax layering is not as strong, which·makes•• visual observation extremely hard. However, interaction between the roads of PZT and silicone nitride parts has been successfully quantified. Using the current set. up and software, the raod width and height have been quantified.

null

['Liu, Chenang', 'Wang, Rongxuan', 'Kong, Zhenyu', 'Babu, Suresh', 'Joslin, Chase', 'Ferguson, James']

2021-11-16T16:20:33Z

2019

Mechanical Engineering

null

['https://hdl.handle.net/2152/90332', 'http://dx.doi.org/10.26153/tsw/17253']

eng

2019 International Solid Freeform Fabrication Symposium

Open

['additive manufacturing', 'surface morphology', 'real-time measurement', 'deep learning']

Real-Time 3D Surface Measurement in Additive Manufacturing Using Deep Learning

Conference paper

https://repositories.lib.utexas.edu//bitstreams/38bf4bcd-8c59-4049-b6e9-1fde4161481b/download

University of Texas at Austin

Layer-wise 3D surface morphology information is critical for the quality monitoring and control of additive manufacturing (AM) processes. However, most of the existing 3D scan technologies are either contact or time consuming, which are not capable of obtaining the 3D surface morphology data in a real-time manner during the process. Therefore, the objective of this study is to achieve real-time 3D surface data acquisition in AM, which is achieved by a supervised deep learning-based image analysis approach. The key idea of this proposed method is to capture the correlation between 2D image and 3D point cloud, and then quantify this relationship by using a deep learning algorithm, namely, convolutional neural network (CNN). To validate the effectiveness and efficiency of the proposed method, both simulation and real-world case studies were performed. The results demonstrate that this method has strong potential to be applied for real-time surface morphology measurement in AM, as well as other advanced manufacturing processes.

null

['Dunbar, Alexander J.', 'Nassar, Abdalla R.', 'Reutzel, Edward W.', 'Blecher, Jared J.']

2021-10-26T17:55:48Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89540

eng

2016 International Solid Freeform Fabrication Symposium

Open

['monitoring', 'powder bed fusion', 'additive manufacturing']

A Real-Time Communication Architecture for Metal Powder Bed Fusion Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/d760433e-88cd-40d5-b440-f15899e42562/download

University of Texas at Austin

Recent advancements in the field of additive manufacturing continue to push its application deeper into commercial use. However, concerns persist regarding the consistency of part quality, methodologies for quality assurance, and cyber-physical system security. These concerns are exacerbated by the closed-system architecture implemented by most commercial powder bed fusion additive manufacturing (PBFAM) machine manufacturers. Though implementation of device and process monitoring equipment is often suggested to address these concerns, deployment is hampered by the inability to extract real-time information from closed systems during the build process, including scanner position, laser power, sensor data, etc. Here, a framework for an open and transparent communication protocol for PBFAM systems is developed and implemented on a 3DSystems ProX-200 machine. Real-time measurement of build process parameters and synchronization with an optical emission sensor is demonstrated. The utility of the protocol and real-time sensing for PBFAM are discussed.

null

['Jariwala, Amit S.', 'Schwerzel, Robert E.', 'Rosen, David W.']

2021-10-04T20:34:38Z

2011

Mechanical Engineering

null

['https://hdl.handle.net/2152/88341', 'http://dx.doi.org/10.26153/tsw/15280']

eng

2011 International Solid Freeform Fabrication Symposium

Open

['Exposure Controlled Projection Lithography', 'stereolithography', 'real-time monitoring system', 'interferometry']

Real-Time Interferometric Monitoring System for Exposure Controlled Projection Lithography

Conference paper

https://repositories.lib.utexas.edu//bitstreams/29594790-2c74-4672-967b-668cbcf8b3c2/download

University of Texas at Austin

Stereolithography is an additive manufacturing process in which liquid photopolymer resin is cross-linked and converted to solid polymer with an ultraviolet light source. Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in which incident radiation, patterned by a dynamic mask, passes through a transparent substrate to cure a photopolymer layer that grows progressively from the substrate surface. In contrast to existing stereolithography techniques, this technique uses a gray-scale projected image, or alternatively a series of binary bit-map images, to produce a three-dimensional polymer object with the desired shape, and it can be used on either flat or curved substrates. Like most stereolithographic technologies, ECPL works in a unidirectional fashion. Calibration constants derived experimentally are fed to the software used to control the system. This unidirectional fabrication method does not, by itself, allow the system to compensate for minor variations, thereby limiting the overall accuracy of the process. We present here a simple, real-time monitoring system based on interferometry, which can be used to provide feedback control to the ECPL process, thus making it more robust and increasing system accuracy. The results obtained from this monitoring system provide a means to better visualize and understand the various phenomena occurring during the photopolymerization of transparent photopolymers.

null

['Ahn, S.', 'Murphy, J.', 'Ramos, J.A.', 'Wood, K.', 'Beaman, J.J.']

2019-10-22T18:27:55Z

2002

Mechanical Engineering

null

['https://hdl.handle.net/2152/76337', 'http://dx.doi.org/10.26153/tsw/3426']

eng

2002 International Solid Freeform Fabrication Symposium

Open

Modification

Real-Time Measurement of Temperature for Control of Laser Surface Modification Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/06d73f6b-81d7-4b41-9367-270d9c1c4d46/download

null

The process of laser surface modification is a complex transient three-dimensional heat conduction problem. A moving heat source and a moving phase boundary further complicate the modeling. This general problem can be simplified using appropriate assumptions resulting in an energy balance equation used to derive a melt depth model as a function of interaction time and laser power input. The model can then be used to design and implement a real-time feedback control scheme. The measurement used for feedback to the control algorithm is the surface temperature. The real-time surface temperature measurements are obtained by using a unique pyrometer arrangement. This measurement scheme allows the pyrometer measurement aperture to directly follow the laser beam path through the entire surface modification process in real-time. Experiments using a Nd:YAG laser were performed on mild steel samples to verify the suggested model’s results.

The Laboratory for Freeform Fabrication gratefully acknowledges the support of the Office of Naval Research for funding the project “Surface Engineering for SFF Processes,” Grant No: N00014-00-1-0334.

null

['Zhao, Xiayun', 'Rosen, David W.']

2021-11-02T20:03:28Z

2017

Mechanical Engineering

null

https://hdl.handle.net/2152/89882

eng

2017 International Solid Freeform Fabrication Symposium

Open

['feedback control', 'real-time', 'in-situ', 'interferometric curing monitoring and measuring', 'exposure controlled projection lithography']

Real-Time Process Measurement and Feedback Control for Exposure Controlled Projection Lithography

Conference paper

https://repositories.lib.utexas.edu//bitstreams/bafb48a7-cdcb-413e-8dda-1ebd6701e3b6/download

University of Texas at Austin

The Exposure Controlled Projection Lithography (ECPL) is an additive manufacturing process that can cure microscale photopolymer parts on a stationary substrate with patterned ultraviolet beams underneath. An in-situ interferometric curing monitoring and measuring (ICM&M) system is developed to measure the ECPL process output of cured height profile. This study develops a real-time feedback control system that utilizes the online ICM&M feedback for automatically and accurately cure a part of targeted height. The experimental results directly validate the ICM&M system’s real-time capability in capturing the process dynamics and in sensing the process output, and evidently demonstrate the feedback control system’s satisfactory performance in achieving the desired height despite the presence of ECPL process uncertainties, ICM&M noises, and computing interruptions. A comprehensive error analysis is reported, implying a promising submicron control with enhanced hardware. Generally, the study establishes a paradigm of improving additive manufacturing with a real-time closed-loop measurement and control system.

null

['Jones, Harrison H.', 'Kwatra, Abhishek', 'Jariwala, Amit S.', 'Rosen, David W.']

2021-10-07T15:21:21Z

2013

Mechanical Engineering

null

['https://hdl.handle.net/2152/88479', 'http://dx.doi.org/10.26153/tsw/15413']

eng

2013 International Solid Freeform Fabrication Symposium

Open

['Exposure Controlled Projection Lithography', 'real-time monitoring system', 'interferometry', 'photopolymerization']

Real-Time Selective Monitoring of Exposure Controlled Projection Lithography

Conference paper

https://repositories.lib.utexas.edu//bitstreams/688ac6f2-723d-4704-964c-85fbd32bc073/download

University of Texas at Austin

Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in which incident radiation, patterned by a dynamic mask, passes through a transparent substrate to cure photopolymer which grows progressively from the substrate surface. We present here a novel method of capturing useful information about the curing process from a simple, inexpensive, real-time monitoring system based on interferometry. This approach can be used to provide feedback control to the ECPL process, thus making the process more robust and increasing system accuracy. The results obtained from this monitoring system provide a means to better visualize and understand the various phenomena occurring during the photopolymerization of transparent photopolymers. In order to lessen the measurement error, caused by internal diffraction within the substrate, the interferometry system has been designed such that the laser light used can be selectively targeted. This selective monitoring approach is experimentally validated to measure the height and profile of the cured part in real-time.

null

['Knoppers, G. E.', 'Gunnink, J. W.', 'van den Hout, J.', 'van Vliet, W. P.']

2019-12-05T17:20:17Z

2004

Mechanical Engineering

null

['https://hdl.handle.net/2152/78650', 'http://dx.doi.org/10.26153/tsw/5706']

eng

2004 International Solid Freeform Fabrication Symposium

Open

Graded Material

The Reality of Functionally Graded Material Products

Conference paper

https://repositories.lib.utexas.edu//bitstreams/43b4ab9e-df5e-4906-8ddd-9050fef1aada/download

null

Rapid Manufacturing utilizes the application of different materials in parts by stacking a sequence of layers. Based on the requirements of the part, mixtures of materials, so-called Functionally Graded Materials, can be used to compose the product functionality. This process depends completely on the availability of CAD information of the part geometry. Unfortunately, commercially available CAD-systems do not allow the design of graded material structures. TNO developed a computer tool which enables the user to specify Functionally Graded Materials. The system is based on a new approach to define the material composition at any point in the solid.

null

['Chen, X.', 'Wang, D.', 'Jiang, T.', 'Xiao, H.']

2021-11-16T15:05:46Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90306', 'http://dx.doi.org/10.26153/tsw/17227']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['disturbance parameter', 'disturbance', 'control-oriented', 'realtime', 'powder bed fusion', 'additive manufacturing']

Realtime Control-Oriented Modeling and Disturbance Parameterization for Smart and Reliable Powder Bed Fusion Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/6582a52b-dd4e-46ed-ad10-799149f597a5/download

University of Texas at Austin

The vision of sustainable mass customization calls for additive manufacturing (AM) processes that are resilient to process variations and interruptions. This work targets to pioneer a system-theoretical approach towards such a smart and reliable AM. The approach is based on control-oriented modeling of the process variations and on closed-loop model-based controls that facilitate in-situ adjustment of the part quality. Specifically, one focused example is laser-aided powder bed fusion. Building on the in-layer precision heating and solidification, together with layer-by-layer iterations of the energy source, feedstock, and toolpath, we discuss mathematical abstractions of process imperfections that will not only understand the intricate thermomechanical interactions but are also tractable under realtime computation budgets. In particular, we develop and validate a surrogate modeling of in-process disturbances induced by the periodic in- and cross-layer thermomechanical interactions. This control-oriented disturbance modeling allows for the adoption of high-performance control algorithms to advance AM quality in a closed loop, and we show a first-instance study on the effect of repetitive controls in reducing melt-pool variations in the periodic energy deposition.

null

['Hu, X.', 'Jiang, T.', 'Lin, F.', 'Sun, W.']

2019-09-23T16:51:59Z

2000

Mechanical Engineering

null

['https://hdl.handle.net/2152/75968', 'http://dx.doi.org/10.26153/tsw/3067']

eng

2000 International Solid Freeform Fabrication Symposium

Open

Boolean

Reasoning Boolean Operation for Modeling, Simulation and Fabrication of Heterogeneous Objects 417

Conference paper

https://repositories.lib.utexas.edu//bitstreams/094f9da6-6187-4af8-a5b0-1821177b084d/download

null

An approach using reasoning Boolean operation to model heterogeneous object is presented. Algorithm in the reasoning Boolean operation consists of merging and extraction operation. This algorithm models heterogeneous object at multi-volume level. Due to its CAD-based nature, the model can be implemented with advanced CAD/CAE/CAM software for integrated design, simulation, and prototyping fabrication. Example of using the developed modeling technique to construct the heterogeneous composite unit cells, to perform integrated design and analysis, and to develop a pseudo-processing algorithm for layered fabrication of heterogeneous object is also presented.

We gratefully acknowledge the support from NSF 9980298 project funding to graduate student T. Jiang during the course of this research.

null

['Gan, M.X.', 'Wong, C.H.']

2021-11-02T19:21:53Z

2017

Mechanical Engineering

null

https://hdl.handle.net/2152/89872

eng

2017 International Solid Freeform Fabrication Symposium

Open

['selective laser melting', 'additive manufacturing', 'LAS', 'glass-ceramic', 'spodumene']

Recapitulation on Laser Melting of Ceramics and Glass-Ceramics

Conference paper

https://repositories.lib.utexas.edu//bitstreams/cde1b983-4cbd-415f-8baf-33e2ffbb392c/download

University of Texas at Austin

Additive manufacturing of ceramics and glass-ceramics is becoming important due to demands for high-performance applications and requirement for customizations. This is also due to the high cost incurred by conventional methods for producing prototypes and functional end parts of such inorganic materials. Despite the advantages that are already evident for direct laser melting of metals, in-process challenges such as thermal stress induced cracks and laser-material interactions have slowed down the progress and adoption of direct laser melting for these inorganic and non-metallic materials. Nevertheless, several works have been carried out to improve the process of direct laser melting of ceramics and glass ceramics despite the various challenges posed. In this article, we recapitulate past studies and update the progress on the additive manufacturing of ceramics and glass ceramics in particular by direct laser melting. In addition, we discuss the relevance of laser melting of ceramics and glass-ceramics for future roadmap.

null

['Hilmas, Greg E.', 'Lombardi, John L.', 'Hoffman, Robert A.', 'Stuffle, Kevin']

2018-11-14T21:03:10Z

1996

Mechanical Engineering

doi:10.15781/T2W37MF7G

http://hdl.handle.net/2152/70267

eng

1996 International Solid Freeform Fabrication Symposium

Open

['EFF', 'CAD', 'freeform fabrication technologies']

Recent Developments in Extrusion Freeform Fabrication (EFF) Utilizing Non-Aqueous Gel Casting Formulations

Conference paper

https://repositories.lib.utexas.edu//bitstreams/08118833-e622-4068-b15b-179861d91d3d/download

null

Extrusion Freeform Fabrication (EFF) was shown to be an extremely versatile method for fabricating Functionally Graded Materials (FGMs) The approach is inexpensive and potentially feasible for grading between any thermodynamically compatible ceramic-metal, ceramic-ceramic, or metal-metal material combination. Several material systems were investigated in this study including alumina-304 stainless steel, zirconia-304 stainless steel, alumina-Inconel 625, zirconiaInconel625, alumina-nickel aluminide, zirconia-nickel aluminide, titanium carbide-InconeI625, titanium diboride-nickel aluminide, and tungsten carbide-nickel aluminide. A controlled gradient was demonstrated between the end members for all of the above compositions. The FGMs were hot pressed to achieve near theoretical densities, providing flexural strengths as high as 1000 MPa for the zirconia-304 stainless steel FGM. The FGM systems developed in this program have a wide variety of potential commercial and government applications including cutting tools and other components requiring wear resistant surfaces, aircraft engine and automotive engine components, light and heavy armor systems, and electrical insulators and heat-sinks for the electronics industry, to name a few

null

['Cesarano TIl, Joseph', 'Baer, Thomas A.', 'Calvert, Paul']

2018-11-28T17:21:40Z

1997

Mechanical Engineering

doi:10.15781/T2GF0NG4Z

http://hdl.handle.net/2152/70322

eng

1997 International Solid Freeform Fabrication Symposium

Open

['freeform fabrication', 'dense ceramic', 'Robocasting']

Recent Developments in Freeform Fabrication of Dense Ceramics From Slurry Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/89ef35a3-f69a-4e59-bd7e-1ee2d9e522aa/download

null

A freeform fabrication technique for dense ceramics and composites has been developed. The technique requires less than 2 volume percent of organic additives and relies on the principle of layerwise deposition of highly loaded colloidal slurries. Components can be manufactured into complex geometries with thick solid sections as well as with thin-walled sections with high aspect ratios. Process feasibility and quality is dependent on the processing parameters ofsolids loading, slurry rheology, deposition rate, and drying rate. These interrelated parameters must be controlled so that sintering defects are prevented and shape tolerance is maintained. A review of this freeform fabrication technique, called robocasting, will be discussed for fabrication of aluminum oxide parts. Recent developments for a finite element analysis technique for modelling the drying process will also be presented.

null

['Himmer, Thomas', 'Techel, Anja', 'Nowotny, Steffen', 'Beyer, Eckhard']

2019-10-24T18:25:06Z

2002

Mechanical Engineering

null

['https://hdl.handle.net/2152/77419', 'http://dx.doi.org/10.26153/tsw/4508']

eng

2002 International Solid Freeform Fabrication Symposium

Open

Laser Processing

Recent Developments in Laminated Tooling by Multiple Laser Processing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/a0f79144-1172-4224-ac78-93fed8a7bbbd/download

null

This research and development project is founded by the German Federal Ministry of Education and Research (BMBF) within the framework concept "research for the production of tomorrow" and cared by the agency “Production and Production Technologies” (PFT) at the Forschungszentrum Karlsruhe.

null

['Walczyk, Daniel F.', 'Hardt, David E.']

2018-11-14T16:42:40Z

1996

Mechanical Engineering

doi:10.15781/T2D795W86

http://hdl.handle.net/2152/70237

eng

1996 International Solid Freeform Fabrication Symposium

Open

['PEL die fabrication', 'CNC machining', 'laminated construction']

Recent Developments in Profiled-Edge Lamination Dies for Sheet Metal Forming

Conference paper

https://repositories.lib.utexas.edu//bitstreams/f517161d-a3cb-4860-ad17-ae2c9639fac4/download

null

The Profiled-Edge Lamination (PEL) method was developed by the Walczyk and Hardt as an improvement oer the current method of stacking and bonding contured laminations in terms of the lead-time and cost of toolIng development for sheet metal forming dies. It is also a viable alternative to conventional CNC-machining of such dies. In pursuit of successful commercial realization of the PEL method in industry, this paper discusses several important issues including: • the origin of this method and advantages over other tooling techniques • the general procedure for creating PEL machining instructions • determining the geometric error introduced by the straight bevel approximation • the propensity for PEL die delamination from high forming loads • methods for cutting bevels into die laminations and • the machinery needed for PEL die fabrication. Future research and developmental work on the PEL die method will also be outlined.

null

['Cesarano Ill, Joseph', 'King, Bruce H.', 'Denham, Hugh B.']

2019-03-01T17:32:48Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73516', 'http://dx.doi.org/10.26153/tsw/666']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['ceramic powder', 'colloidal slurries']

Recent Developments in Robocasting of Ceramics and Multimaterial Deposition

Conference paper

https://repositories.lib.utexas.edu//bitstreams/fcdde209-c17b-46ae-965b-046d907fbb79/download

null

Robocasting is a freeform fabrication technique for dense ceramics and composites that is based on layer-wise deposition of highly loaded colloidalslurries. The process is essentially binderless with less than 1% organics and parts can be fabricated, dried, and completely sintered in less than 24 hours. This overview will highlight recent materials developments for structural applications and modelling of slurry flow. Fabrication of preforms for alumina/metal composites will be discussed as well as techniques for multimaterial deposition in both graded structures and discrete placement of fugitive materials.

null

['Wang, Pan', 'Nai, Mui Ling Sharon', 'Tan, Xipeng', 'Vastola, Guglielmo', 'Raghavan, Srinivasan', 'Sin, Wai Jack', 'Tor, Shu Beng', 'Pei, Qing Xiang', 'Wei, Jun']

2021-10-27T21:37:15Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89622

eng

2016 International Solid Freeform Fabrication Symposium

Open

['3D printing', 'titanium alloy', 'microstructure', 'mechanical properties', 'phase transformation', 'porosity', 'surface finishing', 'residual stress', 'simulation']

Recent Progress of Additive Manufactured Ti-6Al-4V by Electron Beam Melting

Conference paper

https://repositories.lib.utexas.edu//bitstreams/8a187aa1-aca9-4744-bfe7-0a446fccb16f/download

University of Texas at Austin

Electron beam melting (EBM) is one of the powder-bed fusion additive manufacturing technologies. This technology is very suitable for producing near-net-shape small to medium volume metallic parts with complex geometries. However, layer-by-layer fusion step introduces rapid thermal cycles, which results in a different microstructure as compared to their cast or wrought counterparts. Therefore, the microstructure and mechanical properties produced by EBM must be better understood and in turn to control the microstructure for requirements of some specific applications. Accordingly, in this paper, an insight will be provided on the effort of understanding the microstructure and mechanical properties from atomic scale to real complex big-sized industrial components. The spatial- and geometrical-based microstructure and mechanical properties of EBM Ti-6Al-4V as well as the effect of heat treatment on them were investigated using atom probe tomography, transmission electron microscopy, scanning electron microscopy, optical microscopy, x-ray diffraction, x-ray computed tomography, nanohardness testing, microhardness testing, tensile testing and finite element simulations. The microstructure and deformation mode depend on both the build thickness and build height which are closely linked to the heat input and the cooling rate in EBM process. Furthermore, the control of microstructure by varying the process parameters and heat treatment schemes was also proposed. By using these findings, an impeller prototype with a base diameter of 100 mm, a height of 53 mm and thinnest sections of ~0.7 mm and a turbine blade prototype with dimensions of 180×70×360 mm were successfully fabricated by EBM. These components exhibited an overall improved combination of strength and ductility as compared to the counterparts fabricated by conventional methods. These results revealed that EBM is a promising method for fabricating complex-shaped industrial components with superior mechanical performance for practical application.

null

['Kirka, Michael', 'Bansal, Rohan', 'Das, Suman']

2021-09-29T20:18:39Z

2009-09

Mechanical Engineering

null

['https://hdl.handle.net/2152/88212', 'http://dx.doi.org/10.26153/tsw/15153']

eng

2009 International Solid Freeform Fabrication Symposium

Open

['scanning laser epitaxy', 'single crystal superalloys', 'nickel-based superalloys', 'single-crystal turbine engine components']

Recent Progress on Scanning Laser Epitaxy: A New Technique for Growing Single Crystal Superalloys

Conference paper

https://repositories.lib.utexas.edu//bitstreams/d0ffab28-a80a-4540-86ea-6da61d610386/download

University of Texas at Austin

This paper presents recent progress on scanning laser epitaxy, a laser manufacturing technique being developed for achieving single crystal growth in nickel‐based superalloys. Investigations have been performed for creating monolithic deposits on like chemistry single‐crystal nickel superalloy substrates. Progress in the areas of microstructure development and process control will be discussed in the context of repairing high‐value single‐crystal turbine engine components. This work is funded by the Office of Naval Research contract #N00173‐07‐1‐G012.

null

['Dwivedi, Rajeev', 'Sinha, Ayush', 'Ebburu, Pranav', 'Saxena, Yash', 'Haque, Shabab', 'Kulkarni, Shaunak']

2021-10-28T20:41:24Z

2016

Mechanical Engineering

null

https://hdl.handle.net/2152/89695

eng

2016 International Solid Freeform Fabrication Symposium

Open

['work envelope', 'solid freeform fabrication', 'drive limitations']

A Reconfigurable System to Enhance the Work Envelope of a Solid Freeform Fabrication System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/d177bbcc-c3e4-4d83-a317-464913c778bb/download

University of Texas at Austin

Size and aspect ratio of parts created by Solid freeform fabrication systems is limited by the configuration of equipment. Also referred to as Axes, the maximum reach of material deposition end effector determines the maximum size of the part that can be built. Inherent to most the SFF system is the drive configuration that limits the extent of the reach of the end effector. This paper proposes an alternate architecture that overcomes the drive limitations and hence provides an ability to enhance the work envelope. Two systems proposed include – (1) Cartesian axis stacking and (2) Common Vehicle arrangement. The system drive may be built such that multiple units can be combined and reconfigured to expand the total work envelope.

null

['Sutton, Austin T.', 'Kriewall, Caitlin S.', 'Leu, Ming C.', 'Newkirk, Joseph W.']

2021-11-11T14:52:22Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90208', 'http://dx.doi.org/10.26153/tsw/17129']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['recyclability', 'reuse', '304L', 'stainless steel', 'selective laser melting']

Recyclability of 304L Stainless Steel in the Selective Laser Melting Process

Conference paper

https://repositories.lib.utexas.edu//bitstreams/27413124-ef05-43ca-ac9a-66fd13abb558/download

University of Texas at Austin

During part fabrication by selective laser melting (SLM), a powder-bed fusion process in Additive Manufacturing (AM), a large amount of energy is input from the laser into the melt pool, causing generation of spatter and condensate, both of which have the potential to settle in the surrounding powder-bed compromising its reusability. In this study, 304L stainless steel powder is subjected to five reuses in the SLM process to assess its recyclability through characterization of both powder and mechanical properties. Powder was characterized morphologically by particle size distribution measurements, oxygen content with inert gas fusion analysis, and phase identification by X-ray diffraction. The evolution of powder properties with reuse was also correlated to tensile properties of the as-built material. The results show that reused powder coarsens and accrues more oxygen with each reuse. The effects of powder coarsening and oxygen increase on the tensile properties of fabricated parts are being investigated.

null

['Walker, Roo', 'Smith, Tyler', 'Lindahl, John', 'Hershey, Christopher', 'Kunc, Vlastimil', 'Duty, Chad']

2021-12-06T21:49:51Z

2021

Mechanical Engineering

null

['https://hdl.handle.net/2152/90684', 'http://dx.doi.org/10.26153/tsw/17603']

eng

2021 International Solid Freeform Fabrication Symposium

Open

['CF-ABS', 'recycling', 'printability', 'large-scale additive manufacturing', 'LSAM']

Recycling Carbon Fiber Filled Acrylonitrile-Butadiene-Styrene for Large Format Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/de30e1d1-5756-4bd7-969f-1e79d8df8799/download

University of Texas at Austin

The recovery, recycling, and reuse of large format additive manufacturing (LFAM) composite scrap material as a secondary feedstock material is essential for the feasibility of large-scale AM (LSAM) sustainability. Carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS) was recycled and used as a secondary LSAM feedstock material to understand printability behaviors against that of virgin feedstock materials. Each material was printed on the Big Area AM system. Rheological and preliminary fiber length were evaluated. Rheological characterization was used to determine if the recycled feedstock materials were viable for printing. Fiber analysis was performed to gain understanding of fiber degradation in the recycling process. By successfully characterizing the impact of incorporating secondary feedstocks in large-scale AM, a pathway can be defined for further reducing material waste and improving AM sustainability.

null

['Mohammed, Mazher Iqbal', 'Wilson, Daniel', 'Gomez-Kervin, Eli', 'Vidler, Callum', 'Rosson, Lucas', 'Long, Johannes']

2021-11-09T14:29:42Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90080', 'http://dx.doi.org/10.26153/tsw/17001']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['3D printing', 'FFF', 'polymer', 'solar', 'e-waste', 'humanitarian aid']

The Recycling of E-Waste ABS Plastics by Melt Extrusion and 3D Printing Using Solar Powered Devices as a Transformative Tool for Humanitarian Aid

Conference paper

https://repositories.lib.utexas.edu//bitstreams/672d49b3-e773-4d2b-b84b-3395403e2b8c/download

University of Texas at Austin

This study demonstrates the EcoPrinting principal, which makes use of renewable energy to realise a low carbon footprint means of recycling waste plastics into feedstock for Fused Filament Fabrication (FFF) 3D printing. We present our work to date to encapsulate this principal in a singular device, which comprises a nanogrid solar/battery storage unit, a custom made filament extrusion device and modified FFF 3D printer system. We demonstrate that our system is capable of reforming ABS plastics found in electronic waste and converting these into functional items through a melt extrusion and additive manufacturing process. We successfully demonstrate the efficacy of the system to operate using solar derived energy and using the resulting filament to 3D print functional pipe connector components. We conclude Ecoprinting holds considerable potential as a sustainable means of converting waste plastics into functional components. Finally, the portable and self-sufficient nature of the system, Ecoprinting could feasibly could be applied as a cost effective aid solution for vulnerable communities in low socio-economic environments.

null

['Prasad, K. Siva', 'Rathakrishnan, E.', 'Dhande, Sanjay G.']

2019-11-21T18:10:29Z

2003

Mechanical Engineering

null

['https://hdl.handle.net/2152/78551', 'http://dx.doi.org/10.26153/tsw/5607']

eng

2003 International Solid Freeform Fabrication Symposium

Open

Casting Technique

Recycling of RP Models by Solution - Casting Technique

Conference paper

https://repositories.lib.utexas.edu//bitstreams/2e72495f-3da6-4ccf-8079-438f1821c5ac/download

null

Most of the Rapid Prototyping systems process polymeric materials for model making. Increased environmental concerns and waste minimization demands the recycle of these polymeric models. One way is to melt the models and cast it. However, in this method polymer degradation may occur leading to diminished functionality. In the present work a preliminary attempt has been made to reuse the polymer components by dissolving in a suitable solvent and casting the same into the required shape using soft tooling. Acrylonitrile Butadiene Styrene (ABS) polymer components, made by Fused Deposition Modeling (FDM) process were taken for the present study

null

['Engle, J.', 'Nguyen, R.', 'Buah, K.', 'Weaver, J.M.']

2021-11-18T18:15:47Z

2019

Mechanical Engineering

null

['https://hdl.handle.net/2152/90453', 'http://dx.doi.org/10.26153/tsw/17374']

eng

2019 International Solid Freeform Fabrication Symposium

Open

['ambient lighting', 'visual contrast', 'in-process monitoring', 'smart lighting', 'colorization system', '3D printing']

Reducing Computer Visualization Errors for In-Process Monitoring of Additive Manufacturing Systems Using Smart Lighting and Colorization System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/7caa1520-3a7d-42a0-8014-79cccb7c8695/download

University of Texas at Austin

Computer vision systems that monitor additive manufacturing processes are susceptible to producing false-positive errors for defects. Two of the main sources for these errors come from uncontrolled ambient lighting and insufficient visual contrast between prints and their backgrounds. This paper presents a method for controlling ambient lighting and increasing visual contrast for an in-process monitoring system for a 3D printer, using a light-filtering camera enclosure and a smart lighting and colorization system. A single-camera in-process monitoring system was developed and used to visually inspect a series of identical test prints. Various error classes, including false-positive error rates, were tested and measured for the camera system, comparing the results of including a blackout enclosure and a smart lighting system against using the camera system alone. Recommendations for future development of lighting and colorization systems are suggested.

null

['Duty, Chad', 'Failla, Jordan', 'Kim, Seokpum', 'Lindahl, John', 'Post, Brian', 'Love, Lonnie', 'Kunc, Vlastimil']

2021-11-04T14:21:43Z

2017

Mechanical Engineering

null

https://hdl.handle.net/2152/89968

eng

2017 International Solid Freeform Fabrication Symposium

Open

['vertical material deposition', 'z-pinning', 'mechanical anisotropy', 'extrusion-based printing', '3D printing', 'patent-pending']

Reducing Mechanical Anisotropy in Extrusion-Based Printed Parts

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b4bf7556-69d9-48bc-a3d8-329781a08056/download

University of Texas at Austin

The mechanical performance of 3D printed components is highly dependent upon the orientation of the part relative to the build plane. Specifically for extrusion-based printing systems, the bond between successive layers (z-direction) can be 10-25% weaker than in the printed plane (x-y plane). As advanced applications call for fiber reinforced materials and larger print systems (such as the Big Area Additive Manufacturing system) extend the layer time, mechanical performance in the z-direction can decrease by 75-90%. This paper presents a patent-pending approach for improving mechanical performance in the z-direction by depositing material vertically across multiple layers during the build. The “z-pinning” process involves aligning voids across multiple (n) layers, which are then back-filled in a continuous fashion during the deposition of layer (n+1). The “z-pinning” approach has been demonstrated to be an effective approach for increasing the strength (20% increase) and toughness (200% increase) of printed parts in the z-direction.

null

['Forderhase, Paul', 'Corden, Richard']

2018-05-03T17:19:19Z

1993

Mechanical Engineering

doi:10.15781/T27S7J93X

http://hdl.handle.net/2152/65043

eng

1993 International Solid Freeform Fabrication Symposium

Open

['Sinterstation 2000', 'anchors', 'experimental data', 'Thermal Distortion']

Reducing or Eliminating Curl on Wax Parts Produced in the SinterstationTM 2000 System

Conference paper

https://repositories.lib.utexas.edu//bitstreams/4a9f3432-e94a-4153-85ef-bb33d3e40bc3/download

null

['Reeves, P.E', 'Cobb, R.C..']

2019-02-19T20:05:52Z

1998

Mechanical Engineering

null

['https://hdl.handle.net/2152/73442', 'http://dx.doi.org/10.26153/tsw/594']

eng

1998 International Solid Freeform Fabrication Symposium

Open

['Layer Manufacturing Technologies', 'Rapid Tooling']

Reducing the Surface Deviation of Streolithographpy Using an Alternative Build Strategy

Conference paper

https://repositories.lib.utexas.edu//bitstreams/8d4b8d8e-b87a-4370-bc89-4e9ce241c3fa/download

null

Considerable research has been undertaken to assess the suitability of different post-process finishing techniques, when used to reduce the surface deviation of Stereolithography components. Such techniques are however limited, as irregular roughness on the SL master often results in a loss in geometric integrity before the desired finish is achieved. Hence, removing much ofthe design intent and traceabilty within the automated fabrication process. Although a number of research initiatives have been undertaken to design layer manufacturing systems which produce inherently smooth surface, the problem of finishing parts from existing. systems remains. The solution currently under investigation by the author is to develop a smooth build cycle within the SL machine, eliminating the need for costly machine modifications. The solution developed by the author uses a strategy, which relies on both part orientation and a fundamental change to the current SLA build cycle. By orientating parts into an optimum build direction, the paper shows how naturally occurring phenomena within the SL process can be used to produce low roughness over a 50-degree window of surfaces. The paper·goes on to demonstrate how, by using a resin meniscus scanned between layers during the·buildiprocess, this smooth envelope can be extended to encompass 90-degree .of surfaces. By scanning fillets between each layer, a reduction in surface roughness of up to 400% can be achieved on some angled planes. The paper concludes that by using this new build algorithm,·the roughness of SL tool cavities can be maintained below 9Jlm Ra on all surfaces. Hence, reducing or even eliminating the need for post-process finishing on all but the most accurate cavities.

null

['Ullett, Jill S.', 'Chartoff, Richard P.', 'Lightman, Allan J.', 'Murphy, John P.', 'Li, Jinghong']

2018-10-03T15:41:54Z

1994

Mechanical Engineering

doi:10.15781/T2CZ32Q3Z

http://hdl.handle.net/2152/68651

eng

1994 International Solid Freeform Fabrication Symposium

Open

['stereolithography', 'Resin shrinkage', 'vector randomization']

Reducing Warpage In Stereolithography Through Novel Draw Styles

Conference paper

https://repositories.lib.utexas.edu//bitstreams/fc3be269-1239-4e2e-9815-e7ccd6fa9011/download

null

A consistent problem with stereolithography has been part distortion and dimensional inaccuracies caused by resin shrinkage. Resin shrinkage and, thus, warpage occurs during the build process and during the postcure. Build parameters such as draw pattern (the order in which strands are drawn by the laser) and overcure (cure depth minus slice thickness) can affect overall part warpage by minimizing the warpage of individual strands and layers. A software package, PATTERNDRAW, developed at the University of Dayton allows an SLA operator to manipulate vector files and change the pattern by which layers, slices, are filled in. This software was used to study the effects of draw pattelTI, vector segmentation" and cure depth on warpage of parts of different sizes. All parts were made using Ciba-Geigy 5081-1 resin. Moire analysis was used to measure out-of-plane deflections of part surfaces. Result~ indicate that significant reductions in warpage can be achieved by the use of novel draw styles.

null

['Gervasi, Vito R.', 'Cook, Douglas']

2021-09-28T18:27:39Z

2009-09

Mechanical Engineering

null

['https://hdl.handle.net/2152/88148', 'http://dx.doi.org/10.26153/tsw/15089']

eng

2009 International Solid Freeform Fabrication Symposium

Open

['shell-slice', 'decomposition', 'hybrid fabrication', 'least-core', 'lattice structures', 'cellular structures']

Reduction of Complex Objects into Manufacturable Elements Using the Shell-Slice Approach

Conference paper

https://repositories.lib.utexas.edu//bitstreams/4e3f9b98-2a0e-4c09-acf1-34f8a0d2c83e/download

University of Texas at Austin

Software tools for generating a parting surface around a molded part have been available for many years and could be of use for additive fabrication of complex objects. This paper explores the use of software tools such as Materialise Magics Tooling TM and SolidWorks® software to assist in reducing complex objects, such as a lattice structure, into sub-elements free of undercuts and hidden internal geometry. The objective of the proposed Shell-Slice approach is to decompose an object into elements that can be readily machined and created via hybrid fabrication processes. The appeal of hybrid fabrication combined with an automated Shell-Slice approach, is the machinability of each sub-element parting-surface and the remarkable build-speeds and surface-finishes that may be attainable.

null

['Bevan, D. R.', 'Mouton, S. A.']

2020-03-05T20:24:14Z

2006

Mechanical Engineering

null

['https://hdl.handle.net/2152/80158', 'http://dx.doi.org/10.26153/tsw/7179']

eng

2006 International Solid Freeform Fabrication Symposium

Open

FASTOOL

Reduction of Machine Tool Times Through a Software/Hardware Integrated Solution

Conference paper

https://repositories.lib.utexas.edu//bitstreams/bef62a1b-6deb-4f00-bd17-7bdfa788ab94/download

null

Toolmaking is an industry that creates metal moulds, generally of durable tool steels, for producing vacuum-formed and injection moulded plastic parts, which are used in thousands of everyday items such as mobile phones. At present toolmaking is labour intensive with each machining operation requiring manual supervision. The FASTOOL project was a European Union funded collaboration that was aimed at reducing the manpower content of mould toolmaking, and extending the working day. This paper focuses on one element which utilised specially created scheduling and control software that operated an automated overhead gantry system and could remotely start the workshop machines. The software was completely object oriented which allows future proofing by creating new objects for new machines. The results demonstrate that this manufacturing process can be automated, leading to better working conditions for employees and an increase in efficiency and profitability.

null

['Patrick, Steven', 'Nycz, Andrzej', 'Noakes, Mark']

2021-11-11T16:16:29Z

2018

Mechanical Engineering

null

['https://hdl.handle.net/2152/90233', 'http://dx.doi.org/10.26153/tsw/17154']

eng

2018 International Solid Freeform Fabrication Symposium

Open

['reinforcement learning', 'toolpaths', '3D printing', 'additive manufacturing']

Reinforcement Learning for Generating Toolpaths in Additive Manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/188b5ff0-b6f6-4743-904d-65bcc642fb84/download

University of Texas at Austin

Generating toolpaths plays a key role in additive manufacturing processes. In the case of 3-Dimensional (3D) printing, these toolpaths are the paths the printhead will follow to fabricate a part in a layer-by-layer fashion. Most toolpath generators use nearest neighbor (NN), branch-and-bound, or linear programming algorithms to produce valid toolpaths. These algorithms often produce sub-optimal results or cannot handle large sets of traveling points. In this paper, the researchers at Oak Ridge National Laboratory’s (ORNL) Manufacturing Demonstration Facility (MDF) propose using a machine learning (ML) approach called reinforcement learning (RL) to produce toolpaths for a print. RL is the process of two agents, the actor and the critic, learning how to maximize a score based upon the actions of the actor in a defined state space. In the context of 3D printing, the actor will learn how to find the optimal toolpath that reduces printhead lifts and global print time.

null

['Nelson, J.C.', 'Barlow, J.W.']

2018-04-19T18:19:16Z

1992

McDonald Observatory

doi:10.15781/T2RB6WK2Z

http://hdl.handle.net/2152/64403

eng

1992 International Solid Freeform Fabrication Symposium

Open

['SLS model', 'SLS operators', 'SLS machines', 'one-dimensional']

Relating Operating Parameters between SLS Machines which have Different Scanner Geometries and Laser Spot Sizes

Conference paper

https://repositories.lib.utexas.edu//bitstreams/c16e8143-bd9a-497f-9cee-b21590772b60/download

null

As the number of SLS machines in operation increases, the opportunities to share operating parameters with other SLS operators also increases. However, if the machines are not identical down to the spot size of the laser beam, the quality of parts made on each machine can be different. The most likely differences between two SLS machines are the laser spot size and the scanning radius of the optics. The total energy flux to the powder surface is a function of the spot size and the scan speed. The algorithms defined to correct for machine differences are verified both experimentally and numerically using a one-dimensional empirical SLS model.

null

['Capps, Nicholas E.', 'Urban, James S.', 'West, Brian', 'Lough, Cody', 'Replogle, Adriane', 'Hartwig, Troy', 'Brown, Ben', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Kinzel, Edward C.']

2021-11-02T13:30:10Z

2017

Mechanical Engineering

null

https://hdl.handle.net/2152/89796

eng

2017 International Solid Freeform Fabrication Symposium

Open

['engineering properties', 'tensile', 'strength', 'modal properties', 'selective laser melting']

Relating Processing of Selective Laser Melted Structures to Their Material and Modal Properties

Conference paper

https://repositories.lib.utexas.edu//bitstreams/2cde9b1d-64c7-4d95-8641-41c2173ea5bd/download

University of Texas at Austin

Selective Laser Melting (SLM) creates metal parts by fusing powder layer-by-layer. It provides significant design flexibility and the possibility of low-volume production. The engineering properties of the printed metal are a function of the local thermal history. This creates challenges for validating Additively Manufactured (AM) parts. This paper correlates the engineering properties (density, modulus, yield strength and ultimate strength) for tensile test specimens created with different process parameters with the resonant frequencies determined using modal testing. The paper shows that yield and ultimate strengths for these specimens can be determined using modal analysis.

null

['Thomas, Akshay J.', 'Barocio, Eduardo', 'Kapre, Vasudha', 'Pibulchinda, Pasita', 'Nguyen, Felix N.', 'Pipes, R. Byron']

2023-01-26T21:32:39Z

2022

Mechanical Engineering

null

['https://hdl.handle.net/2152/117323', 'http://dx.doi.org/10.26153/tsw/44204']

eng

2022 International Solid Freeform Fabrication Symposium

Open

['Fiber Orientation', 'Spring-in', 'Virtual Characterization']

Relationship between flow-controlled fiber orientation and spring-in deformation in extrusion deposition additive manufacturing

Conference paper

https://repositories.lib.utexas.edu//bitstreams/03c9c4d0-3003-487e-9366-95c0ed275b89/download

null

ctures in the scale of multiple meters owing to enhanced stiffness and lower coefficient of thermal expansion primarily in the printing direction. Developing manufacturing process simulations for EDAM requires extensive material characterization including mechanical, thermal, viscoelastic, and thermomechanical property characterization. Further, varying the bead deposition conditions alter the fiber orientation state of the composite, thereby resulting in different anisotropic material properties. This increases the amount of characterization required to enable the digital twin framework. Therefore, we present a framework to infer the fiber orientation properties by conducting limited tensile tests at the composite coupon level. Using the inferred orientation state, we predict the unmeasured mechanical and thermomechanical properties and bypass the need for their experimental characterization. We present the application of this framework to predict the spring-in deformation of a geometry of interest printed using different process conditions.

null

['Kigure, T.', 'Yamauchi, Y.', 'Niino, T.']

2021-11-18T01:44:24Z

2019

Mechanical Engineering

null

['https://hdl.handle.net/2152/90398', 'http://dx.doi.org/10.26153/tsw/17319']

eng

2019 International Solid Freeform Fabrication Symposium

Open

['PA12', 'microstructure', 'low-temperature process', 'powder bed temperature', 'selective laser sintering']

Relationship Between Powder Bed Temperature and Microstructure of Laser Sintered PA12 Parts

Conference paper

https://repositories.lib.utexas.edu//bitstreams/ae14aedd-18e1-4db8-9205-9db0d707cd99/download

University of Texas at Austin

The microstructure of a part from semi-crystalline polymers used in laser sintering gives a significant impact on the mechanical properties of the parts. The microstructure of laser sintering parts depends on powder bed temperature. If the powder bed temperature can be set in a wide range, it is also possible to control the microstructure of a part. The authors have been introducing a modified laser sintering process, namely low temperature process. The process allows powder bed temperature being set wide range. In this research, relationship between microstructure of PA12 parts by low-temperature process and powder bed temperature is investigated. As a result, high strength and crystallinity were obtained in high powder bed temperature, and high ductility and low crystallinity were obtained in low powder bed temperature. This result indicates that parts having the desired mechanical properties can be obtained by controlling the powder bed temperature.

null

['Cariapa, V.', 'Liang, S.K.', 'Brower, W.E.']

2018-04-12T18:28:25Z

1991

Mechanical Engineering

doi:10.15781/T2639KN98

http://hdl.handle.net/2152/64281

eng

1991 International Solid Freeform Fabrication Symposium

Open

['Department of Mechanical and Industrial Engineering', 'Taguichi system', 'stereolithography']

The Relationship of Process Characteristics of Stereolithography to Prototype Dimensions

Conference paper

https://repositories.lib.utexas.edu//bitstreams/d53fae1c-07ef-4847-ba22-92771ac9de3f/download

null

A characteristic of the modem·day world is a continuous need ever changing designs of high quality products. This characteristic, along>with lower cost of comp\.iting,has led to the development of novel methods for reducing the cycle time of product development order for companies to gameracompetitiveedge.I>esk top. manufacturing or rapid prototyping such fieldoftechl1()logywhich• enablesco.mpaniesto rapidlyproduee.a three· dimension<model from a computer data base. An overview of this rapidly expanding field is given in IS Among the more common ofthese modem processes arestereolithography (SLI) [2,3], the DTM process [6], powder metallurgyprototyping [4], and metal spraying of stereolithography pam [8]. An overview ofthe stereolithographyprocess has been presented in [3]. process characteristics and a generalprojection oftoleraneevalues of finished been identified in [1,7]. However, the relationship between the two has the available literature. This research focuses on· developing a more quantitative understanding of important process parameters and dimensions of finished pam that are using stereolithography.

null

['Bocking, Chris', 'Rennie, Allan E. W.', 'Bennett, G.R.']

2019-09-23T17:05:31Z

2000

Mechanical Engineering

null

['https://hdl.handle.net/2152/75974', 'http://dx.doi.org/10.26153/tsw/3073']

eng

2000 International Solid Freeform Fabrication Symposium

Open

Electroformed

Relationships Between Wall Thickness and Erosion Depth of Thin Walled Electroformed EDM Electrodes Produced From RP Models 469

Conference paper

https://repositories.lib.utexas.edu//bitstreams/c4442fc0-391d-4cce-8859-9aa45bbddf77/download

null

Metal filled thin walled electroformed EDM electrodes, fabricated using RP models, have been shown to be an effective route to producing die sink electrodes. However, due to the nature of electroforming, there are certain limits to the maximum depth of erosion of cavities that can be achieved, this being related to the electrode wall thickness. This initial study examines the relationship between the electrode wall thickness and depth of erosion.

null

['Jones, Jason', 'McNutt, Phil', 'Tosi, Riccardo', 'Perry, Clinton', 'Wimpenny, David']

2021-10-06T21:51:25Z

8/16/12

Mechanical Engineering

null

['https://hdl.handle.net/2152/88455', 'http://dx.doi.org/10.26153/tsw/15392']

eng

2012 International Solid Freeform Fabrication Symposium

Open

['remanufacturing', 'laser cladding', 'inspection', 'additive manufacturing (AM)', 'adaptive machining', 'hybrid processing', 'repair']

Remanufacture of Turbine Blades by Laser Cladding, Machining and In-Process Scanning in a Single Machine

Conference paper

https://repositories.lib.utexas.edu//bitstreams/bf64cc28-b99e-44a8-ae6e-ee32fb920294/download

University of Texas at Austin

Remanufacturing is one of the most efficient ways of recycling worn parts because it consumes only a fraction of the energy, cost, and material required for new parts. Remanufacture of engineering components typically entails serial labor intensive and operator skill sensitive processes, often requiring parts to move between manufacturers and subcontractors. Unfortunately the logistics and quality assurance measures required for effective remanufacturing currently restrict its implementation primarily to high value components (e.g. turbine blades, blisks, etc.). This research reports progress toward an integrated production system which combines laser cladding, machining and in-process scanning in a single machine for flexible and lean remanufacturing.

null

['Chadha, Charul', 'Patternson, Albert E.', 'Allison, James T.', 'James, Kai A.', 'Jasiuk, Iwona M.']

2021-11-18T19:11:01Z

2019

Mechanical Engineering

null

['https://hdl.handle.net/2152/90473', 'http://dx.doi.org/10.26153/tsw/17394']

eng

2019 International Solid Freeform Fabrication Symposium

Open

['damage repair', 'additive manufacturing', 'fused deposition modeling', 'plastic materials']

Repair of High-Value Plastic Components Using Fused Deposition Modeling

Conference paper

https://repositories.lib.utexas.edu//bitstreams/b7fbb409-14d3-4321-a881-d85dfe68571a/download

University of Texas at Austin

Recent focus on light-weight design and fuel efficiency in several sectors (such as aerospace and automotive), as well as advances in polymer technologies, have made plastic parts more viable for high-value systems. These are often low-production, high-precise parts which require expensive tooling for traditional manufacture, making them difficult to reproduce later; this is especially true when the original tooling is no longer available, and full additive manufacturing (AM) is infeasible. This study explores the application of fused deposition modeling (FDM - extrusion-based AM) in the repair of cracks, chips, and broken features in such plastic parts. A framework for repairing various kinds of plastic parts using FDM is presented, including establishment of repair candidacy, selection of repair material and parameters, post-processing, and repair evaluation. Three case studies, one repairing an optimized truss, one exploring the use of sewing-stitch patch patterns, and one replacing a broken part feature, were developed to demonstrate the presented concepts.

null