Surface Deformation and Residual Stress and Their Correlation on Laser Shock Peened Thin-wall TC17 Titanium Alloy

Surface plastic deformation and residual compressive stress are typical characteristics of laser shock peened thin-walled metal structures. Numerical simulation was employed to investigate the distribution of surface plastic deformation and residual stress of TC17 titanium alloy thin-walled structures peened by square and round laser spots. Further, the internal relationship between surface plastic deformation and residual stress was expounded. The results show that both surface plastic deformation and residual compressive stress show obvious functional relationships with laser shock peening parameters（laser energy, impact times）. A power function is identified between surface plastic deformation and laser shock peening parameters.An exponential function is identified between surface residual stress and laser shock peening parameters. Further, the surface residual stress is exponentially related to plastic deformation. Square laser spot and circular laser spot peening induced compressive residual stress can reach 560 MPa and 520 MPa on 1.0 mm thin-walled TC17 titanium alloy, respectively.