Effect of cryogenic nano-cutting on surface integrity of the single crystal γ-TiAl alloy via atomic simulation

Molecular dynamics simulations are performed to investigate the cryogenic nano-cutting of monocrystalline gamma-TiAl alloy. Effects of different low-temperature conditions on material properties and surface integrity are systematically investigated, aiming to predict the optimal low-temperature processing conditions of monocrystalline gamma-TiAl alloy in the nano-cutting process. The results show that the cohesive energy of monocrystalline gamma-TiAl alloy increases at low temperature, but the low temperature is not the necessary condition for forming residual compressive stress on the machined surface. In the stable cutting stage, the heat dissipation rate of the workpiece increases linearly with the increase of the cutting distance, which is consistent with the stability of the Newtonian layer temperature. In addition, the evolution process of the dislocation band in the subsurface damage layer is explained from the atomic perspective. By comparing and analyzing the surface integrity under different cryogenic cutting, the optimal cryogenic cutting temperature is about 173 K.