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 |
Fundamental physics effects of background gas species and pressure on vapor plume structure and spatter entrainment in laser melting |
Author(s) |
Saad Khairallah, Michael Stokes, Alexey Volkov, Sasha Rubenchik |
On-Site Speaker (Planned) |
Saad Khairallah |
Abstract Scope |
First-principles modeling, based on the direct simulation Monte Carlo (DSMC) method, is applied to quantitatively explain the physics of stainless-steel (SS316L) vapor plumes and jets and powder particle entrainment under conditions relevant to laser welding and laser powder bed fusion additive manufacturing. The simulations are performed for different background gas species (argon, helium, and neon) at background gas pressures from 0.1 to 5 bar and molten pool temperatures from 3250 K to 4000 K. This study emphasizes that the ambient gas species and the pressure in the build chamber should be treated as process parameters that are as important as controlling laser power and scan speed when trying to prevent defects. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Based on LLNL document review and release number LLNL-JRNL-829362. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |