Finite Element Analysis on the Chip Formation Mechanism of Titanium Alloy's High Speed Machining

Serrated chip may occur easily during machining titanium alloys.It will cause the periodical vibration of the cutting force,which may affect the surface integrity of the machined workpiece surface as well as tool life.However,there is no consensus on the titanium alloys' serrated chip formation mechanism.With a rigid visco-plastic model and normalized Cockroft and Latham separation criterion,orthogonal cutting process of titanium alloy Ti6Al4V at high speed is simulated.According to the results,it is verified that titanium alloys' chip formation can be explained well by the periodical crack theory and the changes of stress states in the primary shear zone are the main reason of crack's initiation and propagation.The result is correspondent with the chip micrograph of Ti6Al4V and can provide both theoretical and technical help for high speed machining of titanium alloys.