About this Abstract |
Meeting |
2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024)
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Symposium
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2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024)
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Presentation Title |
The Effects of Laser Absorption and Shielding in Plasma Vapor Jets Induced by Continuous Wave Laser Irradiation of Tungsten |
Author(s) |
Michael Stokes, Alexey Volkov, Saad Khairallah |
On-Site Speaker (Planned) |
Michael Stokes |
Abstract Scope |
Laser powder bed fusion (L-PBF) experiments show that absorption of laser radiation by the evaporated vapor jet can negatively impact print quality at high laser powers. This plasma shielding becomes more prevalent during the processing of refractory metals used in high-entropy alloys due to the high laser intensity that is required for melting. The present work numerically investigates the effect of plasma formation in the evaporated jet from bulk tungsten targets for various laser powers using an in-house, hybrid computational model. The model combines a non-equilibrium collision-radiation model of ionization and absorption with the direct simulation Monte Carlo (DSMC) method. The simulations reveal the range of conditions where radiation absorption in the jet strongly affects the thermal state of the irradiated target. Under conditions typical for L-PBF, the simulations indicate that a supersonic vapor microjet is formed and the plasma shielding effect is strong. LLNL-ABS-863662 |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |