Atomic-scale study of vacancy defects in SiC affecting on removal mechanisms during nano-abrasion process

摘要

The mechanical properties of mono-crystalline SiC with vacancy defects in fixed abrasive polishing processes are not well known at the nanometric scale. In the molecular dynamic (MD) simulation, the removal mechanism of mono-crystalline SiC substrates with vacancy defects is investigated. So is the wear mechanism of diamond abrasives explored. The simulation result reveals that the increase of vacancy defects in SiC substrates leads to reduced von Mises Stress, however, to increased temperature of SiC substrates during nano-abrading process. More vacancy defects are found to lead higher removal efficiency and less subsurface damage on SiC substrates. Furthermore, the diamond abrasives are worn out through a combination of thermo-chemical wear, graphitization wear and abrasive wear in the simulation.