Study of stress-assisted nano-cutting mechanism of gallium arsenide

The high-performance manufacturing of hard-brittle materials by single-point diamond turning (SPDT) is a very active and challenging research area. The stress-assisted nano-cutting is a promising method for improving the machinability of hard-brittle materials. However, the simulation results in the existing stress-assisted nanocutting model would contradict the actual condition due to the pre-stress being released before tool entry into the workpiece. A modified stress-assisted nano-cutting model with a virtual boundary between the workpiece and tool is proposed for the first time in this paper to investigate the nano-cutting process of GaAs material under different external stresses. The emergence of an atomic flow vortex during stress-assisted nano-cutting significantly enhances the quality of the machined surface, leading to a substantial reduction in both machined surface roughness (34.4 %) and subsurface damage (56.2 %), compared to the normal nano-cutting. By evaluating surface roughness, subsurface damage depth, morphological accuracy, cutting force, and removal efficiency, a pre-strain of 0.06 is determined to be the optimal pre-strain for stress-assisted nano-cutting. Moreover, the selection of optimal pre-strain remains unaffected by variations in the nano-cutting depth. TEM results demonstrate that the nano-cutting mechanism elucidated by the MD analysis accurately reflects the genuine deformation of the GaAs material.