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Materials Science and Engineering
Mechanical and Aerospace Engineering Faculty Research & Creative Works
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- 3D printers (6)
- Binders (5)
- Deposition (5)
- Extrusion (5)
- Laser heating (5)
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- Manufacture (5)
- Selective laser sintering (5)
- Additive manufacturing (4)
- Sintering (4)
- Bioactive glass (3)
- Ceramic (3)
- Compressive strength (3)
- Mechanical properties (3)
- Repair (3)
- 3D Printing (2)
- Additive Manufacturing (2)
- Cellular Automata (2)
- Curve Fitting (2)
- Extrusion Freeforming (2)
- Fabrication (2)
- Freeform (2)
- Fused Deposition (2)
- Geometrical features (2)
- Heterogeneous Nucleation (2)
- Laser Depositions (2)
- Laser metal deposition (2)
- Microstructure (2)
- Morphological Evolution (2)
- Porosity (2)
- Process parameters (2)
Articles 61 - 71 of 71
Full-Text Articles in Mechanical Engineering
Aqueous-Based Extrusion Fabrication Of Ceramics On Demand, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas, Michael W. Hayes
Aqueous-Based Extrusion Fabrication Of Ceramics On Demand, Michael S. Mason, Tieshu Huang, Robert G. Landers, Ming-Chuan Leu, Greg Hilmas, Michael W. Hayes
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Aqueous-Based Extrusion Fabrication is an additive manufacturing technique that extrudes ceramic slurries of high solids loading layer by layer for part fabrication. The material reservoir in a previously developed system has been modified to allow for starting and stopping of extrusion process on demand. Design pros and cons are examined and a comparison between two material reservoir designs is made. Tests were conducted to determine the optimal deposition parameters for starting and stopping of the extrudate on demand. The collected test data is used to create a process model that describes the relationship between ram velocity and material extrusion rate. …
Fracture Toughness Of Ceramic Moulds For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Von Richards
Fracture Toughness Of Ceramic Moulds For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Von Richards
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ice patterns can be used to make ceramic investment moulds for metal castings. Owing to the characteristics of ice, the ceramic mould must be made at subzero temperatures and consequently, requires a different formulation than shells built at room temperature. Success of this process depends greatly on the fracture toughness of mould materials. The present paper describes the experimental results of fracture toughness of mould materials processed from different compositions. The Taguchi method was used to reduce the trial runs. The parameters considered included the ratio of fibre containing fused silica and aluminosilicate powders, the volume of binder and the …
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
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.
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
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.
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
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 …
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
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
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 …
Study Of Ceramic Slurries For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Harish Jose, Von Richards
Study Of Ceramic Slurries For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Harish Jose, Von Richards
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ice patterns generated by rapid freeze prototyping or a molding process can be used to make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries must be poured around the pattern and cured at sub-freezing temperatures. Success of this process depends greatly on the mold strength after the gelation of the slurries. This paper describes the experimental results of the mold strength after the gelation of the slurries under different compositions. The parameters considered include mixing time, alumino-silicate vs. fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled …
Characterization And Modeling Of Local Electromechanical Response In Stress-Biased Piezoelectric Actuators, N. Navapan-Traiphol, Robert W. Schwartz, Daniel S. Stutts, J. Wood
Characterization And Modeling Of Local Electromechanical Response In Stress-Biased Piezoelectric Actuators, N. Navapan-Traiphol, Robert W. Schwartz, Daniel S. Stutts, J. Wood
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Numerous investigators have explored the factors that contribute to the high electromechanical performance of stress-biased actuators with particular attention being given to the importance of the extrinsic (domain wall translation) response mechanism. Based on the variation in lateral stress through the thickness of the piezoelectric layer within these devices, it has been suggested that the piezoelectric coefficient varies as a function of position within the layer, though no direct evidence has been previously presented. In this study, the results of Moire interferometry investigations of local strains within these devices are reviewed. The technique permits effective depth-profiling of local deformations at …
System Integration And Real-Time Control Architecture Of A Laser Aided Manufacturing Process, Mallikharjuna R. Boddu, Robert G. Landers, Srinivas Musti, Sanjeev Agarwal, Jianzhong Ruan, Frank W. Liou
System Integration And Real-Time Control Architecture Of A Laser Aided Manufacturing Process, Mallikharjuna R. Boddu, Robert G. Landers, Srinivas Musti, Sanjeev Agarwal, Jianzhong Ruan, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper discusses a hybrid deposition–removal manufacturing system being developed at the University of Missouri--Rolla. The system consists of a laser system, five-axis CNC machining center, and powder feeder system. A description of the control software, real-time control architecture, and integration of various subsystems to build the hybrid system is given. The interaction of the real-time controller with various sensors and subsystems to monitor and regulate the process is presented. The communication between integrated process planning for the system and real–time control is also discussed in this paper.
Elasto-Composition Waves In Inhomogeneous Solids, R. C. Batra, Manfred Wuttig
Elasto-Composition Waves In Inhomogeneous Solids, R. C. Batra, Manfred Wuttig
Mechanical and Aerospace Engineering Faculty Research & Creative Works
No abstract provided.