About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Real Time Imaging for Materials Science and Processing: 10th Anniversary
|
| Presentation Title |
Vapor depression entrapment porosity in high-speed laser melting of metals |
| Author(s) |
Zhengtao Gan |
| On-Site Speaker (Planned) |
Zhengtao Gan |
| Abstract Scope |
Ultra-high-speed laser manufacturing of metals promises transformative productivity, yet the high-power, high-speed regime it demands gives rise to defect-formation mechanisms that remain incompletely understood. In-situ megahertz synchrotron X-ray imaging across five alloys reveals a new pore-formation mechanism above 1 m/s: recurrent contact between the tailed vapor depression and the melt-pool boundary entraps vapor as pores. We term this vapor depression entrapment porosity (VDEP). VDEP onset collapses onto a universal dimensionless criterion that jointly combines a vaporization Péclet number and the Prandtl number, enabling its prediction across all five alloys. Beyond subsurface porosity, VDEP reveals a previously unrecognized origin of surface balling, complementing the conventional Plateau–Rayleigh instability interpretation and linking internal defects to surface instability. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Characterization, Solidification |