Rake angle effect in cutting-based single atomic layer removal

When minimum cutting depth is down to a single atomic layer, two portions of the cutting tool, namely, cutting edge and lowest atoms of the cutting tool, are involved in the cutting-induced material removal. Correspondingly, there are different critical rake angles for those two portions of the tool, different from the nominal rake angle in conventional cutting and edge radius-induced effective rake angle in nanocutting. Both they should be considered in atomic and close-to-atomic cutting to obtain the defect-free processed surface with an ideal crystalline structure. Molecular dynamics modelling is carried out to investigate the critical rake angles to enable single atomic layer removal on monocrystalline Cu (1 1 1) surface. The analysis results clearly indicate that the critical rake angles of nanometric cutting edge and the lowest tool atoms for single atomic layer removal are among the range of (–70°, –65°) and (–17°, –14°), respectively. To achieve single atomic layer removal, the tool edge radius is suggested to be not greater than 2 nm. The research findings would provide theoretical guidelines to the cutting tool design for the application of mechanical cutting of high-performance atomic scale devices.