Dislocation evolution in nanoscratching the CVD diamond film: Discrete dislocation dynamics simulation and experiments

Dislocation behavior has been considered as the crucial reason for micro-scale plasticity and micro-damage of the diamond. In this research, based on the theory of discrete dislocation dynamics (DDD), the nanoscratch model was established to investigate the dislocation evolution and stress distributions of the chemical vapored deposition (CVD) diamond film, and further supported by experimental study. Well-designed nanoscratch experiments were performed to validate the simulation results. It can be found that dislocation multiplication occurred along the scratch path. Besides, the dislocation pile-up and local stress concentration are easier to be found inside the smaller grain stress concentration. And it causes the occurrence of crack initiation near the grain boundary. Graphic abstract: [Figure not available: see fulltext.]