Study on stress-wave propagation and residual stress distribution of Ti-17 titanium alloy by laser shock peening

Laser shock peening has advantages of less restriction, better reinforcement, stronger controllability, and so on, which could greatly improve the fatigue properties of the material compared with traditional processes. In this paper, dual phase titanium alloy Ti-17 has been studied, and numerical simulation has been taken to analyze the stress-wave propagation rules in Ti-17 titanium alloy plates with different thicknesses. In addition, the distribution of residual stress which is obtained by experiments is used to verify the accuracy of the above rules. Furthermore, the variation rules of fatigue characteristics of plates with different thicknesses under the same laser shock peening parameters are analyzed. The results show that due to the reflection of the stress-wave, the final residual stress and fracture toughness of the specimen decrease, resulting in an increase of the crack propagation rate and crack length. Since thinner specimens have a higher frequency of stress-wave reflection, they show greater effects.