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Full-Text Articles in Mechanical Engineering
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez
Electronic Theses and Dissertations
Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …
Development And Characterization Of Bound Metal Deposition Including Laser Ablation, Alexander J. Watson
Development And Characterization Of Bound Metal Deposition Including Laser Ablation, Alexander J. Watson
Electronic Theses and Dissertations
Bound Metal Deposition (BMD) is a novel metal additive manufacturing technology in which a metal powder-binder composite paste is layer-wise extruded to form a part, which is then debound and sintered into a solid metal part. Although promising, BMD suffers from shrinkage-induced warpage and an inability to produce fine length scale features. This research addresses these problems by: (1) characterizing warpage of planar parts, and (2) developing a novel laser ablated process to create fine length scale features. First, a 12-factor resolution IV fractional-factorial design of experiments (DOE) was conducted to determine the warpage of planar parts as a function …
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock
Electronic Theses and Dissertations
This work focuses on evaluating different modeling approaches and model parameters for thermoplastic AM, with the goal of informing more efficient and effective modeling approaches. First, different modeling approaches were tested and compared to experiments. From this it was found that all three of the modeling approaches provide comparable results and provide similar results to experiments. Then one of the modeling approaches was tested on large scale geometries, and it was found that the model results matched experiments closely. Then the effect of different material properties was evaluated, this was done by performing a fractional factorial design of experiments where …
A Study Of Reduced Activation Ferritic Martensitic Metal Core Wire For Wire Arc Additive Manufacturing, Alexander L. Reichenbach
A Study Of Reduced Activation Ferritic Martensitic Metal Core Wire For Wire Arc Additive Manufacturing, Alexander L. Reichenbach
Electronic Theses and Dissertations
This study seeks to determine the technical feasibility of fabricating reduced activation ferritic martensitic (RAFM) steel parts, using a wire arc additive manufacturing (WAAM) process. The WAAM process, manufactures a part by depositing layers of metal onto a substrate to build a large scale near net shape part. RAFM alloy steels are next generation steels designed to resist radiation effects in the radiation intense working environments, such as nuclear reactors. To achieve this, process development and testing to design the WAAM production process with the custom RAFM filler wire was carried out. Several welding waveform modes were tested, and it …
Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes
Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes
Electronic Theses and Dissertations
GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. The first of its kind, GRCop-84, was specifically designed for the environments seen by channel cooled main combustion chamber liners. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop- 42 was developed. In recent years, NASA has successfully additively manufactured GRCop with comparable material characteristics to wrought GRCop using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate cooling channels as …
Development Of Material For 3d Printed Habitats With Extraplanetary Applications, Taylor Wait
Development Of Material For 3d Printed Habitats With Extraplanetary Applications, Taylor Wait
Electronic Theses and Dissertations
3D printing, also called Additive Manufacturing, has increasingly become a focus for research because of the potential to replace complicated assemblies or complex parts with a single printed item. The space industry is very interesting in studying 3d printing with parts being tested and used on rockets, a 3D printer being installed at the International Space Station and is being developed for use in manned exploration of extraplanetary bodies to build habitats. To encourage teams from around the world to develop technologies and materials for autonomous habitat construction using minimal Earth exports, NASA created the 3D Printed Habitat Challenge. NASA …