Molecular dynamics study of the removal mechanism of SiC in a fixed abrasive polishing in water lubrication

Abstract The mechanical removal mechanism of SiC substrates in the water-lubricated environment is investigated by molecular dynamics (MD) simulation. The surface quality, subsurface damage, removal efficiency and structural phase transition of SiC substrates were analyzed in a fixed abrasive polishing (FAP) under various water film thickness and external load. In water-lubricated environment, a small number of water molecules are pressed on the interface between the SiC substrates and the diamond abrasive. The results show that the largest pressing depth decreases with the increase of the water film thickness, contrary to the effect of the external load. The phase transition and the frictional heat both decrease as the pressing depth decreases, which further reduces the stress and temperature of the substrate in the FAP. The water layer has positive impact on the surface roughness and subsurface damage depth. Furthermore, the removal efficiency in the water-lubricated nano-abrading is lower than that in the dry process. Our researches benefit to understand the mechanical removal mechanism of SiC substrates under a water-lubricated environment and give theoretical guide for improving the machining technology of FAP.