Influence of High Pressure Water-Jet Assisted Turning on Surface Residual Stresses on Ti-6AL-4V Alloy by Measurement and Finite Element Simulation

摘要

Residual stresses from the machining process can cause severe failure due to fatigue and stress corrosion. The depth profile of residual stress was measured for high-pressure water-jet assisted machining of Ti-6Al-4V alloy using x-ray diffraction. As comparison, the depth profile of residual stress was also measured for the conventional machined work-piece. The finite element simulation, using the updated Lagrangian formulation was also used to study the dynamic transient process. It was found that the residual stress was a function of machining parameters, such as cutting speed, feed force, depth of cut and particularly the high-pressure jet increases the amount of residual compression stresses in both cutting and feed directions. It is shown that the high-pressure water-jet assisted machining of titanium alloys is beneficial. It reduces shear forces in the secondary cutting zone along the tool/chip interface, reduces the cutting force and introduces compressive residual stress in the finished work-piece.