Molecular dynamics study of crystal orientation effect on surface generation mechanism of single-crystal silicon during the nano-grinding process

Crystal orientation of the crystalline materials surfaces significantly affects the surface generation and subsurface damage of the materials during the ultra-precision machining. This work is based on the molecular dynamics (MD) simulation method to study the nano-grinding process of the single-crystal silicon workpiece with three different types of surface crystal orientations. And the MD simulation results are compared with the experimental results. The results show that the machined surface quality of workpieces with different surface crystal orientations is similar, but the degree of subsurface damage, processing force, phase transition, and internal residual stress is quite different. By comparing all the three types of the workpiece, the surface and subsurface quality of the single-crystal silicon workpiece with {110} surface crystal orientation has a better processing effect. This work reveals the evolution of the crystal structure of single-crystal silicon with different surface crystal orientations and the mechanism of subsurface damage from the atomic point of view.