About this Abstract |
Meeting |
2020 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
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Presentation Title |
Capturing Marangoni Flow via Synchrotron Imaging of Laser Blown Powder Directed Energy Deposition |
Author(s) |
Samuel J. Clark, Yunhui Chen, Lorna Sinclair, Chu Lun Alex Leung, Sebastian Marussi, Robert C. Atwood, Martyn A. Jones, Gavin J. Baxter, Peter D. Lee |
On-Site Speaker (Planned) |
Samuel J. Clark |
Abstract Scope |
Marangoni flow has a substantial influence upon the quality of additively manufactured and repaired aerospace components via laser blown powder directed energy deposition (LBP-DED). However, Marangoni flow is rarely quantified due to the opacity of liquid metals and the necessity for in situ evaluation of this time-transient phenomenon. Here we report the findings of our synchrotron X-ray radiography flow tracking experiments. Dense, highly attenuating tungsten particles are seeded within an aerospace alloy powder feedstock. Due to the large magnitude of the Marangoni flow, rather than perform frame-to-frame tracking, we exploit the elongated streaks as the tracking particle move throughout each exposure time. Through evaluation of the length and path of the streak patterns we quantify the velocity and direction of melt pool flow. This work also provides new insights into how Marangoni flow interacts with pores entrapped within the melt pool, providing valuable process guidance and informing Multiphysics models. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |