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Full-Text Articles in Metallurgy
The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718, Abigail P. Nilan, Jessica M. Fordham
The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718, Abigail P. Nilan, Jessica M. Fordham
Materials Engineering
Inconel 718 (IN718) is a popular wrought superalloy, and is currently being investigated for additive manufacturing (AM) applications in the aerospace industry. However, overaging and the presence of microcracks have caused a significant reduction in properties. The purpose of this study is to meet or exceed the mechanical properties of wrought IN718 by varying the composition and build direction of the AM alloy. Alternative compositions were selected with Oerlilon Metco’s Rapid Alloy Development (RAD) software, and differ in niobium content, which increases the fraction of the primary strengthening phase (γʺ). Direct metal deposition (DMD) was used to fabricate the samples, …
High Cycle Rotating Bending Fatigue Of 6061-T6 Friction Stir Welded Extrusions, John Chang, Travis Miller
High Cycle Rotating Bending Fatigue Of 6061-T6 Friction Stir Welded Extrusions, John Chang, Travis Miller
Materials Engineering
Fatigue testing was done on friction stir welded joints of 6061-T6 aluminum extrusions. Tests were run using a rotating bending fatigue machine at stresses from 111.5 to 138.7 MPa. Failures occurred on the order of 105 to 107 cycles, and an S-N curve was generated based off of the failure results. After the samples failed, the location of the failure and the number of cycles to failure were noted. Fatigue samples were designed in SolidWorks with a tapered 2 inch reduced section. The 2 inch reduced section will include the entire weld region as seen from the microhardness …
Discontinuous Grain Boundaries Of Forged René 41, Steven Crump
Discontinuous Grain Boundaries Of Forged René 41, Steven Crump
Materials Engineering
Forged components must pass a grain size specification (grain size, distribution) for acceptance in an application. The varying amounts of plastic deformation during forging can lead to abnormally large recrystallized grain sizes in certain regions of the part, which will not pass specification. The question exists whether these abnormally coarse grains are truly comprised of poly crystalline fine grains with grain boundaries resistant to etching techniques. To investigate this abnormal grain size effect, a cross section of a forged René 41 nickel-based superalloy aircraft engine ring was cut and sectioned into six segments. Those segments were then prepared for microstructural …
Characterization Of The Relationship Between The Microstructure And Tensile Strength Of Annealed Ti-6al-4v, Aldo Corona
Characterization Of The Relationship Between The Microstructure And Tensile Strength Of Annealed Ti-6al-4v, Aldo Corona
Materials Engineering
Tensile coupons of Ti-6Al-4V were heat treated at varying annealing temperatures from 1200°F (648°C) to 1450°F (787°C) at 50°F (23°C) increments for 1 hour. The samples were air cooled to room temperature or furnace cooled to 800°F (426°C) followed by air cooling to room temperature. Four tensile coupons were treated at each annealing temperature and cooling rate. Alpha case was observed to form on the surface of the samples post heat treatment with a maximum depth of 25 µm (.001 in). Samples were tensile tested for their ultimate tensile strength, yield strength, and percent elongation. Samples across all annealing temperatures …