Molecular Dynamics Analysis of Subsurface Brittleness Mechanism of Nanocrystalline 3C-SiC Rough Friction Surface

Abstract

To study the effect of polycrystalline 3C-SiC rough friction surface on the mechanism of subsurface brittleness during nanocrystalline grinding. The mechanism of subsurface brittleness in the nano-grinding process of polycrystalline 3C-SiC friction surface is analyzed by molecular dynamics method. Combined with the characteristics of polycrystalline grains constructed by Voronoi method, the initial grinding model of rough friction surface polycrystalline 3C-SiC and diamond abrasive particles is constructed. The processing mechanism of 3C-SiC is analyzed by post-processing methods such as dislocation defect analysis, atomic arrangement analysis and stress analysis. At 2.6nm, "stress concentration" occurs between the abrasive particles and the workpiece, forming a "heart-shaped" force shape. The larger the grain size, the smaller the crystal hardness, the greater the possibility of crystal fracture, and it is obvious in the larger crystal size, crystal fracture and vacancy at 8nm. The results show that the rough friction surface of polycrystalline 3C-SiC helps to reduce the damage deformation of the subsurface, and the crossing mechanism between grain and grain boundary can also effectively improve the damage of the subsurface.