Browsing by Subject "tensile behavior"
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
Item Additively Manufactured Haynes 230 by Laser Powder Directed Energy Deposition (LP-DED): Effect of Heat Treatment on Microstructure and Tensile Properties(University of Texas at Austin, 2021) Muhammad, Muztahid; Ghiaasiaan, Reza; Gradl, Paul R.; Shao, Shuai; Shamsaei, NimaThe microstructure and tensile mechanical properties of Haynes 230 fabricated through laser powder directed energy deposition (LP-DED) were investigated, varying temperature heat treatments between 900°C to 1177°C following deposition. Scanning electron microscopy (SEM) was employed for microstructural analysis, whilst tensile testing was utilized to evaluate the room temperature mechanical properties of the alloy. In an as-deposited state, the initial microstructure consisted of cellular γ and M6C/M23C6 carbides. The cellular regions seem to be fully dissolved upon solutionizing at 1177°C for 3 hours. Following post-deposition heat-treatments, the carbides were observed to precipitate and grow along the grain boundaries as well as in the interior of grains. Solutionizing at 1177°C for 3 hours following stress-relieving yielded better ductility and had an insignificant effect on the strength.Item The Effects of Powder Recycling on the Mechanical Properties of Additively Manufactured 17-4 PH Stainless Steel(University of Texas at Austin, 2018) Nezhadfar, Pooriya Dastranjy; Soltani-Tehrani, Arash; Sterling, Amanda; Tsolas, Nicholas; Shamsaei, NimaThe booming interest in Additive Manufacturing (AM), is seeing a rising number of industries and research entities adopting this technology into their manufacturing practices. Of particular interest is Laser Powder Bed Fusion (L-PBF) process, a common AM method for fabricating metallic components. However, one obstacle is the high cost of powder feedstock. A popular tactic to offset this cost is to reuse the powder between prints, but there is no in-depth understanding of how the powder feedstock may change or affect the mechanical properties of the produced parts. By incorporating unique powder/part characterization methods, this study quantifies the rheological properties of continually recycled 17-4 precipitation hardening (PH) stainless steel (SS) powder through successive printing of mechanical test specimens. The AM specimens are subjected to tensile tests, to correlate mechanical behavior to changing powder quality, including particle size/shape distribution, flowability, and density.Item Fatigue Behavior and Failure Mechanisms of Direct Laser Deposited Inconel 718(University of Texas at Austin, 2016) Johnson, Alexander S.; Shuai, Shao; Shamsaei, Nima; Thompson, Scott M.; Bian, LinkanItem Monotonic and Cyclic Tensile Properties of ABS Components Fabricated by Additive Manufacturing(2014) Ziemian, C.W.; Cipoletti, D.E.; Ziemian, S.N.; Okwara, M.N.; Haile, K.V.An investigation of tensile strength and cyclic tension-tension fatigue behavior has been performed on layered ABS components fabricated by fused deposition modeling (FDM). Experimentation was designed to focus specifically on the effect of specimen mesostructure on monotonic tensile behavior and tensile-fatigue life. Analyzed mesostructures include unidirectional laminae with parallel fiber orientations ranging from θ = 0° (aligned with the loading axis) to θ = 90° (perpendicular to the loading axis), and alternating laminae with a layering pattern of θ°/(θ-90°) fiber orientations. The unidirectional 0° specimens achieved the greatest tensile strength and effective elastic modulus, while the alternating +45°/-45° specimens displayed the best fatigue performance of the specimens tested. Results highlight the anisotropic behavior of FDM components and suggest that the tensile behavior is improved by aligning the fibers of unidirectional laminae more closely with the axis of the applied stress. In addition, the specimens with θ°/(θ-90°) fiber orientations displayed incrementally improved tensile properties and fatigue performance from an apparent offsetting effect that results from alternating laminae. The fracture surfaces of the specimens were analyzed using scanning electron microscopy in order to gain further insights into the fatigue damage and failure mechanisms.