Abstract:By SHPB (Split Hopkinson Pressure Bar) test study conducted, the relation of stressstress change of Ti6Al4V under condition of high stress change rate was obtained to fit out a new JC constitutive equation parameters model of Ti6Al4V. Based on this, a simplified twodimensional (2D) model for highspeed milling Ti6Al4V based on ABAQUS/Explicit software analysis was established, and studied with simulation. The simulation results show that thermoplastic instability and plastic side flow is the main cause for saw tooth chip. The chip sawtooth degree Gs decreases when increasing rotating speed, while it increases when increasing feed speed. Useful understanding of the forming process of sawtooth chip is made, which provides reference for selection of machining parameters of highspeed milling Ti6Al4V. Actual highspeed milling experiments were carried out. Experiments show that chip shape of the simulation and experimental results agree well.