Mechanism of chip-formation in nanometric cutting of single-crystal copper by molecular dynamics

Extensive molecular dynamics simulations have been taken out to study the mechanism of chip formation for Nano scale cutting of single crystal copper. A novel method is proposed to identify the propagation of dislocations. It's discovered that under all of the cutting orientations and directions, the chip formation is all due to plastic deformation caused by slipping of atoms on the (111) planes, which belong to the slip system of single crystal copper. For most of the cutting orientations, max shear stress does not locate on (111) planes but there are no slipping on the planes where the max shear stress locates. The slipping occurs on (111) planes where shear stress has exceeded the critical shear stress of (111) orientation. The critical shear stress is approximately 1.5 GPa under the machining parameters adopted. Calculation of local stress is according to the mechanical definition of stress, instead of viral theory. GPU based parallel computing MD codes are developed for the simulation, using CUDA of NVIDIA Corporation.