1. School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China;
2. Beijing Research Institute of Mechanical & Electrical Technology, Beijing 100083, China
To study the influence of hydrogenation on deformation and cutting mechanism of TA15 alloy, tensile test and cutting experiment with different hydrogen content are performed to obtain the mechanical properties, cutting force and the differences in microstructure characteristics of serrated chip. The results show that the yield strength ratio decreases, the plasticity enhances with high hydrogen content and its working hardening is serious. Hydrogen promotes the thermal softening effect, and the higher hydrogen content, the lower critical cutting speed which causes the decrease of cutting force. The difference of plastic deformation characteristics in different regions can be observed in the serrated chip of the as-received and low-hydrogenated groups, the uniform plastic deformation exists in the serrated unit, and the local severe plastic deformation exists in the shear band, which verifies the occurrence of adiabatic shear. However, the microstructure with high hydrogen content has high consistency without local severe plastic deformation. The serrated chip morphology shows the feature of decreasing serration, so it can be inferred that the hydrogen improves the plasticity of the alloy and inhibits the local severe plastic deformation, which significantly improves the cutting performance of TA15 alloy.