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Full-Text Articles in Engineering
Layer-To-Layer Feedback Control For Direct Energy Deposition Additive Manufacturing, Michelle Gegel
Layer-To-Layer Feedback Control For Direct Energy Deposition Additive Manufacturing, Michelle Gegel
Doctoral Dissertations
"Additive manufacturing (AM) has garnered much attention in recent years, some calling it the fourth industrial revolution. It was first used to create rapid prototypes, although recent efforts have been made to advance the technology towards production of functional parts. This requires advancement in the materials used in AM, as well as the ability to produce quality parts repeatably. More specifically, direct energy deposition (DED) of metal powders is a process capable of producing and repairing parts with complex geometries; however, it is not widely used in industry due to challenges with quality control. In this process, metal powder is …
Fabrication, Characterization Of High-Entropy Alloys And Deep Learning-Based Inspection In Metal Additive Manufacturing, Wenyuan Cui
Doctoral Dissertations
"Alloying has been used to confer desirable properties to materials. It typically involves the addition of small amounts of secondary elements to a primary element. In the past decade, however, a new alloying strategy that involves the combination of multiple principal elements in high concentrations to create new materials called high- entropy alloys (HEAs) has been in vogue. In the first part, the investigation focused on the fabrication process and property assessment of the additive manufactured HEA to broaden its engineering applications. Additive manufacturing (AM) is based on manufacturing philosophy through the layer-by-layer method and accomplish the near net-shaped components …
Design, Fabrication, And Characterization Of Functionally Graded Materials, Sreekar Karnati
Design, Fabrication, And Characterization Of Functionally Graded Materials, Sreekar Karnati
Doctoral Dissertations
“The aim of this research was to investigate the feasibility of fabricating custom designed, graded materials using Laser Metal Deposition (LMD) that will cater for functionality and unconventional repair. The ultimate goal of the project is to establish the versatility of LMD for fabricating advanced materials and tackling problems that have been conventionally difficult or in cases infeasible. In order to accomplish these goals, this research involved investigations into, the feasibility of using elemental powders as modular feedstocks, the feasibility of fabricating tailored gradients with these custom compositions, and finally leveraging the advantages of grading materials using LMD to successfully …
Remanufacturing Of Precision Metal Components Using Additive Manufacturing Technology, Xinchang Zhang
Remanufacturing Of Precision Metal Components Using Additive Manufacturing Technology, Xinchang Zhang
Doctoral Dissertations
"Critical metallic components such as jet engine turbine blades and casting die/mold may be damaged after servicing for a period at harsh working environments such as elevated temperature and pressure, impact with foreign objects, wear, corrosion, and fatigue. Additive manufacturing has a promising application for the refurbishment of such high-costly parts by depositing materials at the damaged zone to restore the nominal geometry. However, several issues such as pre-processing of worn parts to assure the repairability, reconstructing the repair volume to generate a repair tool path for material deposition, and inspection of repaired parts are challenging. The current research aims …
Ti-Fe Intermetallics Analysis And Control In Joining Titanium Alloy And Stainless Steel By Laser Metal Deposition, Wei Li
Masters Theses
"Direct fusion joining titanium alloy and stainless steel can cause brittle Ti-Fe intermetallics which compromise the mechanical properties of diffusion bonds between titanium alloys and stainless steel. Therefore, filler metals are required as transition layers. In this research, stainless steel metallic powder was directly deposited on the titanium alloy substrate by laser beam, the Ti-Fe intermetallic phases formed in this process were investigated through analyzing fracture morphology, phase identification, and Vickers Hardness Number (VHN). After that, Laser Metal Deposition (LMD) was applied to explore a new fabricating process to join Ti6Al4V and SS316. A transition composition route was introducedTi6Al4V → …
Numerical Modeling Of Heat Transfer And Fluid Flow In Laser Metal Deposition By Powder Injection, Zhiqiang Fan
Numerical Modeling Of Heat Transfer And Fluid Flow In Laser Metal Deposition By Powder Injection, Zhiqiang Fan
Doctoral Dissertations
"Laser metal deposition is an additive manufacturing technique which allows quick fabrication of fully-dense metallic components directly from Computer Aided Design (CAD) solid models. A self-consistent three-dimensional model was developed for the laser metal deposition process by powder injection, which simulates heat transfer, phase changes, and fluid flow in the melt pool, The governing equations for solid, liquid and gas phases in the calculation domain have been formulated using the continuum model. The free surface in the melt pool has been tracked by the Volume of Fluid (VOF) method, while the VOF transport equation was solved using the Piecewise Linear …