Effect of Repeated Nanocutting on Surface Quality and Subsurface Damage of γ-TiAl Alloy

Y Liu and RC Feng and P Yao and HY Li and H Cao and CL Lei and JH Li, RARE METAL MATERIALS AND ENGINEERING, 52, 3507-3514 (2023).

DOI: 10.12442/j.issn.1002-185X.20220764

In this paper, the repeated nanocutting process of single crystal gamma- TiAl alloy was simulated by molecular dynamics method. The evolution of cutting force and microstructure defects in the repeated nanocutting process was studied. The roughness and residual stress of the machined surface were analyzed, and the difference between the repeated nanocutting and the single cutting was discussed. The results show that the repeated nano-cutting process is accompanied by the formation and annihilation of dislocations, and the fluctuation of dislocation line length in the second cutting process is less than that in the first cutting process, and the cutting state is more stable. The cutting force increases rapidly in the initial stage of machining, and then the cutting force enters the stable machining stage. At the same time, it is found that the cutting force of the second cutting is less than that of the first cutting. After the second cutting, the residual stress distribution is more uniform and the residual compressive stress of the machined surface increases due to the twice extrusion of the tool. Secondary machining can improve surface quality and reduce subsurface damage, while the increase in residual compressive stress and energy required for machining reduces the plasticity of the machined surface, so that the third machining has no obvious improvement in surface and subsurface quality.

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