The effects of polycrystalline 3 C-SiC with different roughness coefficients on the crystal structure of nano-grin ding based on molecular dynamics

Abstract

To investigate the effect of different roughness subsurface on the crystal structure and grain boundary changes during polycrystalline 3 C-SiC nanocrystalline grinding. Polycrystalline 3 C-SiC with different roughness subsurface is constructed by Voronoi method, the stress, crystal structure change and grain boundary crossing mechanism of polycrystalline 3 C-SiC are analyzed by molecular dynamics method. Three different roughness surfaces (Ry=0.02 um, Ry=0.04 um and Ry=0.045 um) are selected for analysis, before the nano-grinding process, the polycrystalline 3 C-SiC is first annealed to make the atoms closely arranged and eliminate the vacancy defects inside the grains. Different roughness affects the friction force of polycrystalline 3 C-SiC and changes the deformation of its subsurface. Consequently, affecting the elastoplastic properties of polycrystalline 3 C-SiC. Different roughness will affect the shear force on the polycrystalline 3 C-SiC subsurface, the smaller the roughness, the greater the shear stress on the subsurface. The polycrystalline 3 C-SiC crystal structure with a roughness of Ry=0.04um is most obviously affected, the length of the dislocations it produces is relatively small, and the situation is more obvious at the boundary, fewer internal dislocations indicating internal dislocation slip phenomenon is less and more favorable for processing.