激光冲击强化是一种先进的材料表面抗疲劳制造技术，本文采用正交试验方法研究了激光冲击2050铝锂合金表面残余应力分布规律，获得了优化的激光冲击参数，并在此参数下验证了疲劳寿命增益。研究结果表明：激光冲击强化诱导的残余应力与试样的几何特性相关性较强，而激光冲击参数本身搭接率对残余应力的影响大于激光能量、大于冲击次数，最佳工艺参数为激光功率密度5.30 GW·cm^-2、搭接率50%、2次冲击。采用此参数冲击后260 MPa和200 MPa应力水平下疲劳寿命分别提高了22%和63%。

Laser shock peening (LSP) is an advanced surface modification technique for anti-fatigue manufacturing. In this paper, the orthogonal test method was employed to investigate the distribution of residual stress on the surface of 2050 aluminum-lithium alloy. The correspondingly optimal LSP parameters were obtained. Furthermore, the fatigue life extension was verified with these parameters. Results show that there is a strong correlation between the LSP-induced residual stress and the geometric characteristics of the specimen. For the LSP parameters which affected residual stress, the effect of overlapping rate is greater than laser energy, and further more significant than impact times. The optimal LSP parameters are laser power density of 5.30 GW·cm^-2, overlapping rate of 50%, and peened twice. With the optimal LSP parameters, the fatigue life increased by 22% and 63% at 260 MPa and 200 MPa stress level, respectively.