Experiment and numerical simulation of overlapping laser shock processing in TC4 titanium alloy

In order to study the characteristics of the residual stress field, the effect of laser shock parameters on residual stress field in overlapping area, overlapping laser shock of TC4 Titanium alloy was carried out with high-power Q-switched, pulsed neodymium-glass laser.Then the process of overlapping laser shock was simulated with ANSYS. The numerical results showed good agreement with the experimental data. Without considering the interaction between the shock parameters, increasing the overlapping rate,the laser power density and the laser pulse duration, the surface residual compressive stress and the depth of residual compressive stress field in overlapping zone can be increased. However, if the overlapping rate and laser pulse duration exceeds a threshold value, the depth of residual compressive stress field and the value of surface residual compressive stress in overlapping zone decline respectively with the increase of the overlapping rate and the laser pulse duration.