About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing: Materials Design and Alloy Development V – Design Fundamentals
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Presentation Title |
Directed-energy Deposition of Ti-6Al-4V Alloy Using Fresh and Recycled Feedstock Powders under Reactive Atmosphere |
Author(s) |
Kun Yang, Geoff de Looze, Vu Nguyen, Robert Wilson |
On-Site Speaker (Planned) |
Kun Yang |
Abstract Scope |
This research studies the directed-energy deposition (DED) of Ti-6Al-4V in an argon atmosphere containing oxygen (from air), using both fresh and recycled feedstock powders. The oxygen pickup in the fresh powder build tends to plateau beyond certain oxygen exposure, while the nitrogen pickup keeps increasing. Builds from recycled powder have higher interstitial elements pickup with no apparent saturation. The resulting microstructure comprises full lamellar α+β, formed through the in-situ decomposition of martensite. The α lath thickness is found to increase with air exposure level, due to the increased β transus temperature and martensite start temperature, and the accelerated diffusion-driven phase transformation. Yield strength and ultimate tensile strength models based on oxygen equivalent are proposed. Nitrogen and oxygen in the builds dictate the elongation-to-fracture, with nitrogen content being a more potent factor. Insights into alloy design and microstructure manipulation via interstitial elements addition are provided. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Titanium, Recycling and Secondary Recovery |