A three-dimensional molecular dynamics (MD) model is developed to study the tool/chip interface stress distributions in machining of polycrystalline copper at atomistic scale. Three polycrystalline copper structures with equivalent grain sizes of 12.25, 7.72, and 6.26 nm are constructed for simulation. Also, a monocrystalline copper structure of the same dimension is simulated as the benchmark case. In addition to the grain size, the effects of depth of cut and cutting speed are also considered. The friction force and normal force profiles along the tool/chip interface in both polycrystalline and monocrystalline nano-machining exhibit similar patterns. The reduction in grain size overall increases the magnitude of normal force along the tool/chip interface, but the normal forces in all polycrystalline cases are still smaller than that in the monocrystalline case. In polycrystalline nano-machining, the increase of depth of cut consistently increases the normal force along the entire contact area, but this trend cannot be observed for the friction force. In addition, the stress profiles are also significantly affected by the cutting speed.

This content is only available via PDF.
You do not currently have access to this content.