Investigate on material removal of 3C-SiC crystals in nano-polishing via molecular dynamics

Abstract

While 3C-SiC crystals are widely employed in engineering applications such as aerospace, energy, chemistry, and electronics, the challenge of enhancing surface friction and wear mechanisms in 3C-SiC materials persists. This work focuses on the nano-polishing velocity effect on the material removal mechanism of 3C-SiC crystals in the course of nano-polishing, which is related to material removal, mechanical response, phase transformation, and stress distribution. By employing molecular dynamics (MD) simulations, nano-polishing velocity is modified within a specified range, and its influence on the atomic motion and structural transformation of the workpiece is examined. The simulation results reveal that higher nano-polishing velocities diminish the subsurface damage and the extent of phase transformation induced by nano-polishing. However, the higher velocities also result in reduced machined surface quality and increased residual stress in 3C-SiC crystals. Therefore, it is challenging to address both the surface quality and subsurface quality of the material solely based on nano-polishing velocity. A recommended range of nano-polishing velocity, ranging from 200 m/s to 400 m/s, is deemed appropriate. This work offers a comprehensive understanding of the material removal mechanism of 3C-SiC at the atomic level and holds significant guiding value for achieving ultra-precision machining of surfaces and subsurfaces.