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Freeform Extrusion Of High Solids Loading Ceramic Slurries, Part I: Extrusion Process Modeling, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas Aug 2006

Freeform Extrusion Of High Solids Loading Ceramic Slurries, Part I: Extrusion Process Modeling, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A novel, solid freeform fabrication method has been developed for the manufacture of ceramic-based components in an environmentally friendly fashion. The method is based on the extrusion of ceramic slurries using water as the binding media. Aluminum oxide (Al2O3) is currently being used as the part material and solids loading as high as 60 vol. % has been achieved. This paper describes a novel manufacturing machine that has been developed for the extrusion of high solids loading ceramic slurries. A critical component of the machine is the deposition system, which consists of a syringe, a plunger, …


Freeform Extrusion Of High Solids Loading Ceramic Slurries, Part Ii: Extrusion Process Control, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas Aug 2006

Freeform Extrusion Of High Solids Loading Ceramic Slurries, Part Ii: Extrusion Process Control, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Part I of this paper provided a detailed description of a novel fabrication machine for high solids loading ceramic slurry extrusion processes and presented an empirical model of the ceramic extrusion process, viewing ram velocity as the input and extrusion force as the output. A constant extrusion force is desirable as it correlates with a constant material deposition rate and, thus, good part quality. The experimental results used to construct the model demonstrated that a constant ram velocity will not necessarily produce a constant extrusion force. In some instances the extrusion force increased until ram motor skipping occurred, and process …


Applications Of A Hybrid Manufacturing Process For Fabrication And Repair Of Metallic Structures, Frank W. Liou, Kevin P. Slattery, Mary Kinsella, Joseph William Newkirk, Hsin-Nan Chou, Robert G. Landers Aug 2006

Applications Of A Hybrid Manufacturing Process For Fabrication And Repair Of Metallic Structures, Frank W. Liou, Kevin P. Slattery, Mary Kinsella, Joseph William Newkirk, Hsin-Nan Chou, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Since its appearance, rapid prototyping technology has been of interest to various industries that are looking for a process to produce/build a part directly from a CAD model in a short time. Among them, the direct metal deposition process is the only process which directly manufactures a fully dense metal part without intermediate steps. However, challenges of the direct metal deposition process include building overhang structures, producing precision surfaces, and making parts with complex structures. Coupled between the additive and the subtractive processes into a single workstation, the integrated process, or hybrid process, can produce a metal part with machining …


Evaluation Of Mechanical Properties And Microstructure For Laser Deposition Process And Welding Process, Yaxin Bao, Jianzhong Ruan, Todd E. Sparks, Jambunathan Anand, Joseph William Newkirk, Frank W. Liou Aug 2006

Evaluation Of Mechanical Properties And Microstructure For Laser Deposition Process And Welding Process, Yaxin Bao, Jianzhong Ruan, Todd E. Sparks, Jambunathan Anand, Joseph William Newkirk, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Aided Manufacturing Process (LAMP) can be applied to repair steel die/molds which are currently repaired using traditional welding process in industry. In order to fully understand the advantages of laser deposition repair process over traditional welded-repair process, the mechanical properties such as tensile strength and hardness of H13 tool steel samples produced by these two processes were investigated. The microstructure and fracture surface of the samples were analyzed using optical microscope and SEM (Scanning Electron Microscope). Moreover, depositions on substrates with different shapes were studied to evaluate the performance of LAMP on damaged parts with complicated geometric shape.


Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Joseph William Newkirk, Frank W. Liou Aug 2006

Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Joseph William Newkirk, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser deposition is an effective process for mold and die repair. In order to improve the part repair quality, the process impact on thermal diffusivity and thermal conductivity needs to be understood for laser deposited, welded and virgin H13. In this paper, H13 tool steel samples were made by laser deposition, welding and virgin H13 and then cut into pieces. Experiments were conducted to investigate the thermal diffusivity and conductivity. A laser flash method is used to test these samples. The future work and opportunities are also summarized.


Maxwell-Wagner Relaxations And Their Contributions To The High Permittivity Of Calcium Copper Titanate Ceramics, Wei Li, Robert W. Schwartz Jan 2006

Maxwell-Wagner Relaxations And Their Contributions To The High Permittivity Of Calcium Copper Titanate Ceramics, Wei Li, Robert W. Schwartz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Calcium copper titanate ceramics were fabricated by cold isostatic pressing at various calcination and sintering conditions. Depending on fabrication condition, three electrical responses were observed in the combined modulus and impedance plots, indicating the presence of two Maxwell-Wagner relaxations. These electrical responses show different response to temperature and applied field. The activation energies, as well as the driving force factors, were calculated for these relations. The determined activation energy values are in the range of 0.57 to 0.65 eV. The contribution of Maxwell-Wagner relaxations to the high permittivity of CCTO and related materials is briefly discussed.