Quasicontinuum analysis of the effect of tool geometry on nanometric cutting of single crystal copper

A dynamic multiscale simulation based on quasicontinuum method (QC) has been conducted to study the effect of tool geometry in nanometric cutting process of single crystal copper. In the simulation, the many-body EAM potential is used for the interactions between copper atoms in of the workpiece. The simulation captures the atomistic behaviors of material removal mechanisms from the free surface and the mobility of dislocations and their interactions with the computational cost of local atomistic simulation method. Simulations are performed on single crystal copper to study the atomistic details of material removal, chip formation, sub-surface deformation, and machining mechanism. The simulation results demonstrate that tool edge radius has significant effect on chip formation and subsurface deformation, because the effective rake angle varies with the tool edge radius. In addition, different effective rake angles result in different stress states and smoother surface can be obtained under bigger clearance angle. The variations of tangential force, normal force as well as the ratio of normal force to tangential force are obtained to analyze the effects of tool edge radius, rake angle and clearance angle in quantitative way.