Effect of water medium on material removal and sub-surface defect evolution in nano-cutting of single-crystal γ-TiAl alloy
Jianhua Li, Wei Peng, Liqun Liu, Hui Cao, Zihao Shao, Haiyan Li, Chunli Lei, Ruicheng Feng
Abstract
In this paper, molecular dynamics (MD) simulation has been applied to study the influence of water medium on the nano-cutting process and the evolution of sub-surface defects of single-crystal γ-TiAl alloy. The effect of water medium in the result of cutting force and cutting temperature have been analysed and discussed in the machining process, while the function of common neighbour analysis (CNA) method has been used to research the chip removal mechanism, sub-surface defects and crystal structure changes. The results showed that the extrusion and shear effects of tool removed atoms from the surface of the workpiece. In the meantime, the cooling and lubricating effect of the water medium reduces the cutting temperature and cutting force. Especially, the temperature of the workpiece has a diffusion effect in the cutting process in the absence of the water medium. Some heat was taken away by the water medium, which lead to insufficient nucleation and migration of the dislocation, and high compressive stress was formed during cutting of water-bearing medium.