Residual Stress Relaxation of Ti-6Al-4V Alloy Based on the Variation of Damping Capacity Induced by Warm Laser Peening
J.Z. Zhou, X.K. Meng, W.L. Zhu, X. Feng, J. Sheng and J.Z. Lu
The effects of warm laser peening at different treating temperatures on damping capacity of Ti-6Al-4V titanium alloy were investigated based on the experimental study, the mechanism of damping capacity improvement on Ti-6Al-4V alloy treated by warm laser peening was discussed; moreover, the compressive residual stress (CRS) and its relaxation under vibration condition were simulated by finite element method (FEM), the stability of residual stress in Ti-6Al-4V titanium alloy subjected to warm laser peening processing was revealed based on the creep theory. It is shown that high dislocation density obtained by warm laser peening under the temperature of dynamic strain aging (DSA) is a critical factor for damping capacity improvement. Owing to higher damping capacity introduced by warm laser peening, the vibration stress is reduced and thus causes a lower creep rate and a slower residual stress relaxation speed than laser peening at room temperature.
Keywords: Nd:YAG laser, Ti-6Al-4V alloy, warm laser peening, finite element method (FEM), residual stress relaxation, damping capacity, compressive residual stress (CRS), dynamic strain aging (DSA)