Effects of grinding speeds on the subsurface damage of single crystal silicon based on molecular dynamics simulations

Understanding the damage mechanism of silicon under interfacial shear is vital as it can provide insights for the ultra-precision low damage machining. In this work, the nano-grinding process of single crystal silicon was studied by molecular dynamics (MD) simulations, the damage mechanism of single crystal silicon were analyzed in details under different grinding speeds. The results show that the maximum height of the grinding chip does not always increase with the increase of the grinding speed. When the speed exceeds 150 m/s, more atoms will flow to both sides of the groove. During grinding, the workpiece changes from cubic diamond structure to nondiamond structure and a small amount of hexagonal diamond structure. The Si-II phase was found in the subsurface damage layer. Residual stresses are mainly distributed in the subsurface damage layer (SDL) and do not always show compressive or tensile stresses as the depth increases. This investigation may shed light on the damage mechanism of silicon from an atomic perspective.