Erosion of aluminum-silicon eutectic alloy under compression plasma flows impact

Abstract

The main physical processes occurring during the impact of compression plasma flows with the eutectic silumin surface were investigated. Numerical modeling of heat transfer processes from the shock-compressed layer formed at the surface of the processed sample by the plasma flow was carried out. It was revealed that the plasma impact leads to melting of the near-surface layer and subsequent crystallization, as a result of which a modified layer was formed. The thickness of melted layer was estimated analytically by solving the classical heat conductivity equation. The experimental depth of the melted layer was also determined using scanning electron microscopy by studying samples cross sections. It was found that the calculated values of the melted layer depth exceeded the experimental ones. This effect was explained by the surface erosion during plasma impact with the material. The main erosion mechanisms were discussed. It was found that hydrodynamic movement of the melt was the main mechanism of surface erosion under compression plasma impact on eutectic silumin. A model was proposed to estimate mass loss during plasma treatment. Good agreement between the experimental and calculated data was obtained.