About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing Fatigue and Fracture: Effects of Surface Roughness, Residual Stress, and Environment
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Presentation Title |
Unnotched Fatigue of Inconel 718 Produced by Laser Beam-Powder Bed Fusion at 25 and 600°C |
Author(s) |
Jayaraj Radhakrishnan, Punit Kumar, Shihao Li, Yakai Zhao, Upadrasta Ramamurty |
On-Site Speaker (Planned) |
Punit Kumar |
Abstract Scope |
The microstructures and mechanical properties of the as-built Inconel 718 alloy, produced using laser beam powder bed fusion (LB-PBF) process, were investigated at room temperature (RT) and 600°C. Fatigue strength (σf) at 600 °C is 23% lower than that at RT due to the lower work hardening rate at 600°C, facilitating easy crack initiation at LOFs that are both favorably located and oriented. However, dynamic recrystallization at the crack tip of the specimens tested at 600°C retards the short fatigue cracks (SFCs) and leads to a substantially higher fatigue life as compared to that at RT. Postmortem analyses were utilized for understanding the initiation and growth mechanisms of SFCs and the roles of plasticity/oxidation induced crack closure on them. It shows that the LB-PBF induced microstructural characteristics such as solidification cells with high dislocation density are effective in resisting the growth of SFCs at 600°C, as compared to RT. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, High-Temperature Materials, Mechanical Properties |