About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing: Advanced Characterization with Synchrotron, Neutron, and In Situ Laboratory-scale Techniques III
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Presentation Title |
Operando X-ray Diffraction Study on Phase Transformations in Carbon Steel during Powder Bed Fusion - Laser Beam |
Author(s) |
William Hearn, Sneha Goel, Camille Puazon, Abdul Shaafi Shaikh, Eduard Hryha, Steven Van Petegem |
On-Site Speaker (Planned) |
William Hearn |
Abstract Scope |
The phase transformations in carbon steel during Powder Bed Fusion – Laser Beam (PBF-LB) remain poorly understood. This is due to the complex thermal history of PBF-LB, which involves rapid cooling as well as cyclic reheating during subsequent passes of the laser. The current work involved operando X-ray diffraction measurements at the Swiss Light Source using a miniaturized PBF-LB device to reveal the thermal history and phase transformations for Fe-0.45C steel. Measurements were carried out on specimens in reflection mode to capture the solidification path, as well as on thin wall structures in transmission mode to observe the transformations within the heat affected zone (HAZ). Results revealed that the solidification path followed L→γ→α', while reheating within the HAZ induced carbide formation and the decomposition of retained austenite. These observations were corroborated with detailed ex-situ microstructure analysis (e.g., OM, SEM and EBSD). |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Phase Transformations, Iron and Steel |