A multiscale simulation investigation of dislocation behaviour of PCD failure process

Although polycrystalline diamond (PCD) is ever viewed as brittle materials, it can present strong dislocation activity in certain condition. In this paper, the two-dimensional discrete dislocation plastic (DDP) simulation under fully periodic boundary conditions was employed to study PCD dislocation behaviour. Crystal dissipation and entropy theory were introduced into the computational study to reveal dislocation density evolution and disordered sequence during PCD failure process. Our result showed that the developed model can capture the essential features of PCD dislocation evolution behaviour and realises accurate description of PCD failure process. Investigations of plastic dissipation and dislocation structure evolution reveal that the dislocation structure evolution plays a key role in the fracture process.