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Full-Text Articles in Mechanical Engineering
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 …
Properties Of 25cr7ni Stainless Steel Fabricated Through Laser-Powder Bed Fusion., Arulselvan Arumugham Akilan
Properties Of 25cr7ni Stainless Steel Fabricated Through Laser-Powder Bed Fusion., Arulselvan Arumugham Akilan
Electronic Theses and Dissertations
Stainless steel is a low carbon high alloyed system with higher concentrations of Cr& Ni, which impart high corrosion resistance to them. Alloys with approximately 25% Cr & 7% Ni in their chemical composition are commercially referred to as ‘Super Duplex Stainless Steel’. They have a unique phase composition of approximately 50% ferrite & 50% austenite, yielding a robust combination of high mechanical strength & corrosion resistance. They find extensive interest & application in the fields which demand a longer service life under intense mechanical / corrosive environment such as offshore oil rigs & pipelines in nuclear power plants. Traditional …
Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv
Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv
Electronic Theses and Dissertations
According to the Hall-Petch equation, the refinement of grains in metals increases the yield strength of the material. Austenite grain size influences the fineness of microstructural constituents in the ferrous alloys. It is well studied that cerium and titanium refine the austenite in steels and some gray irons, but no studies have been done to systematically explore the effects of cerium and titanium additions on austenite in ductile iron. This study sought to determine the effects of selected levels of these elements on the grain size within ductile iron. A hypoeutectic iron was chosen for testing as the proeutectic phase …
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 …