Numerical investigation on the residual stress in abrasive waterjet peening

Surface treatments are needed for the inhibition of fatigue cracking on metallic components. Abrasive waterjet peening is a promising method for the surface treatment of metals. Compared to pure waterjet peening, the demands of operating devices are lower for abrasive waterjet peening. The application of water can effectively reduce the friction and the thermal effect, which is beneficial to prevent the surface deterioration induced by the abrasive particles. The generated residual compressive stress is crucial for improving the fatigue performance of the workpiece by counteracting the tensile stress due to the external cyclic load. In the present study, a numerical model for the abrasive waterjet peening of TC4 titanium alloy was established to evaluate the effects of operating parameters on the residual stress. The feasibility of the numerical model is verified by experiments. The results indicated that the water pressure and shot diameter are the most significant parameters in adjusting the magnitude and distribution of residual compressive stress. Moreover, quantitative prediction for residual stress was also conducted through the response surface method.