Serrated chip formation and their adiabatic analysis by using the constitutive model of titanium alloy in high speed cutting

To investigate the cutting mechanism of a new emerging high temperature and high strength titanium alloy named TC21 (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb) using the finite element method (FEM), a modified high temperature split Hopkinson pressure bar (SHPB) test system was employed to obtain the stress-strain curves of TC21 alloy under different temperatures and strain rates. The Johnson-Cook (JC) model was fitted using the data of SHPB test and used to describe the material behavior in the high speed cutting simulation of TC21 alloy. The chip formation simulation and experiment proved that the adiabatic effect is the key factor to lead to the serrated chips in the high speed cutting of TC21 alloy. Furthermore, the comparison of chip formation between simulation and experiment under different tool rake angles showed that the serrated chip of TC21 alloy is sensitive to the tool rake angle.