About this Abstract |
Meeting |
2022 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2022)
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Symposium
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2022 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2022)
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Presentation Title |
Revealing Melt Flow Instabilities in Laser Powder Bed Fusion Additive Manufacturing of Aluminum Alloy via In-situ High Speed X-ray Imaging |
Author(s) |
Qilin Guo, Minglei Qu, S. Mohammad H. Hojjatzadeh, Luis I. Escano, Zachary Young, Kamel Fezzaa, Lianyi Chen |
On-Site Speaker (Planned) |
Qilin Guo |
Abstract Scope |
Laser metal additive manufacturing technologies enable the fabrication of geometrically and compositionally complex parts unachievable by conventional manufacturing methods. However, the certification and qualification of AM parts are greatly hindered by the stochastic melt flow instabilities intrinsic to the process, which have not been explicitly revealed by direct observation. Here, we report the mechanisms of the melt flow instabilities in LPBF-AM process revealed by in-situ high-speed high-resolution X-ray imaging. We identified powder/droplet impact, significant keyhole oscillation, and melting-mode switching as three major mechanisms for causing melt flow instabilities. We demonstrated the detrimental consequences of these instabilities brought to the process, and projected new understanding on the melt flow evolution and keyhole oscillation. This work provides critical insights into process instabilities during laser metal additive manufacturing, which may guide the development of instability mitigation approaches. The results reported here are also important for the development and validation of high-fidelity computational models. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |