| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Solid-State Phase Transformations and Microstructural Evolution
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| Presentation Title |
Time-resolved Synchrotron X-ray Diffraction Studies of Phase Evolution in Ni alloy 718 during Laser Melting |
| Author(s) |
Seunghee Oh, Rachel E Lim, Joseph Aroh, Joseph Pauza, Andrew Chuang, Benjamin J. Gould, Joel V. Bernier, Tao Sun, Robert M. Suter, Anthony D. Rollett |
| On-Site Speaker (Planned) |
Seunghee Oh |
| Abstract Scope |
Laser-based additive manufacturing is accompanied by rapid changes in microstructure, phase, and temperature due to its extreme heating and cooling conditions. In this study, in-situ synchrotron X-ray diffraction was combined with a 520W fiber laser allowing for time-resolved observations of phase evolution in Inconel 718 upon cooling. Due to the high temporal and spatial resolution in the measurement, the rapid evolution of the melted region beneath the surface of the sample can be captured. By analyzing asymmetric peak based on an assumption of overlapped peaks from γ, γ’ and γ”, the relative phase fractions can be quantified. The γ’ and γ” lattice parameters show diverging behavior upon cooling, but they are similar to γ at high temperatures. The evolution of secondary phases is characterized, despite their weak diffraction intensity, because of the relatively small phase amount. Moreover, the thermal history profile was approximated from thermal expansion. |
| Proceedings Inclusion? |
Planned: |