Simulation of the removal mechanism of thermo-oxidized layer and surface morphological evolution on TA15 alloy under nanosecond pulsed laser ablation by multiphase flow model

An Analysis of the Morphology Evolution of YG8 Cemented Carbide by Laser Ablation in the Liquid Phase

“…The number of ablations is 8-9. The surface of the melt pool shows high pressure and high velocity, while the pressure and velocity inside the melt pool are low, so the heat is transferred to the inside, and the vortices converge toward the center of the melt pool as the temperature and velocity decreases, generating upward velocity vectors at the surface of the melt pool, the downward trend is suppressed [27]. However, the upward flow rate on both sides of the melt pool is very high [28], and the pressure inside the melt pool is very high, which remains downward ablated by surface tension and buoyancy.…”

“…The melt pool is kept oscillating under recoil pressure, surface tension, buoyancy, and gravity, and the plasma produced by its ablation produces a shielding effect on the laser ablation [29], resulting in the buildup of the molten cladding, and the laser ablation has no significant change on the melt pool, thus achieving dynamic equilibrium. The surface of the melt pool shows high pressure and high velocity, while the pressure and velocity inside the melt pool are low, so the heat is transferred to the inside, and the vortices converge toward the center of the melt pool as the temperature and velocity decreases, generating upward velocity vectors at the surface of the melt pool, the downward trend is suppressed [27]. However, the upward flow rate on both sides of the melt pool is very high [28], and the pressure inside the melt pool is very high, which remains downward ablated by surface tension and buoyancy.…”