Analysis of High-Speed Cutting Surface Layer Formation and Oxide Layer Thickness Prediction of Titanium Alloy (Ti6Al4V).

This study discusses the surface characteristics of titanium alloy Ti6Al4V during high-speed cutting, especially the effect of cutting speed on surface quality at different measuring scales. The experimental analysis shows that when the feed rate is 0.2 mm, and the detection scale is 1.2 mm, the surface roughness increases first and then decreases with the increase in the cutting speed. When the detection scale is 0.1 mm, the surface roughness continues to increase with the increase in the cutting speed. Based on the experimental results, this study adopted a research method combining experiment and simulation to intensely discuss the difference in the cutting speed's mechanism of influence on surface quality under different detection scales. Based on the first principles, a prediction model for the oxide layer of high-speed cutting titanium alloy was constructed, and experiments verified the model's accuracy. It was found that with the increase in the cutting speed, the cutting surface layer gradually formed a metamorphic layer, and the thickness of the oxide layer gradually increased, and it resultantly fell away. At the same time, the change in material microstructure and phase transition worked together to reduce the machining accuracy. In addition, the content of different components significantly affected the formation mechanism of the oxide layer, significantly increasing the Al content, which affected the oxygen diffusion activation energy and the oxide layer's thickness.