Investigation of cutting force, cutting stress, subsurface deformation, and phase change during the macro and nano cutting process of OFHC copper

In this paper, the FEM and MD method are used to establish macro and nano cutting model of OFHC copper, and the cutting force, cutting stress and subsurface deformation and phase change are compared and analyzed under the macro cutting depth (0.2mm, 0.3mm, 0.4mm) and nano cutting depth (0.8nm, 1.2nm, 1.6nm). Meanwhile, experiments are used to verify the simulated cutting force. The conclusions are below: The change trends of macro and nano cutting force are similar, and the ratios of the cutting forces in x and y directions at different cutting depths are similar. In addition, there are lateral chip both in the macro and nano cutting processes, showing a high degree of consistency. However, the nano cutting stress reached 25 times of that in the macro state. Then it was found that the area of unrecoverable plastic deformation on the surface increased with the increase of the cutting depth during the macro cutting process, but the existence depth of pure plastic deformation remained unchanged within 0.05mm. Although in the nano cutting process, the proportion of FCC crystals converted to HCP crystals remains unchanged as the cutting depth increases, but the existence range is increasing. Finally, the amplitude and change trend of experimental and the simulated cutting force are highly consistent, which verifying the rationality of the macro simulated cutting model.