目的 研究激光冲击强化中冲击角度对强化效果的影响。方法 采用波长为1064 nm、脉冲能量为7 J、脉冲宽度为12 ns的YAG激光器对TC4钛合金表面进行冲击强化处理，得到经不同偏振方向、冲击角度冲击后的材料的表面形貌、硬度和残余应力。通过菲涅耳定律分析了不同偏振光斜冲击加工效果的差异。结果 随着冲击角度的增大，冲击后形成的微坑深度逐渐减少，且正交偏振光减少的程度大于平行偏振光减少的程度，在超过30°的时候尤为明显。随着冲击角度的增大，试样表面显微硬度逐渐下降，当用平行偏振光斜冲击时，硬度下降较慢；而用正交偏振光斜冲击且冲击角度超过15°时，硬度下降较快。随着冲击角度增加，由于“残余应力洞”的影响，中心残余压应力值先增大后减少。结论 在一定情形下，选用一定角度的斜冲击可以有效避免残余应力洞的产生。该研究得到的结论可以为复杂结构件激光冲击强化冲击轨迹规划提供一定的参考。

The work aims to study the influence of shock angles on the strengthening effect for laser shock peening. TC4 ti-tanium alloy samples were treated by YAG laser system with wavelength of 1064 nm, pulse-energy of 7 J and pulse-width of 12 ns. The surface topography, residual stress and microhardness of the samples shocked in different polarization directions by differ-ent shock angles were obtained. The difference of impact processing effect for different polarized oblique laser was analyzed by the Fresnel‘s law. With the increase of the shock angle, the pit depth of the samples caused by the shock gradually reduced. The depth decrease by the orthogonal polarization laser was more obvious compared with that by the parallel polarization laser, particularly when the angle exceeded 30?. As the shock angle increased, the microhardness of samples gradually decreased. The microhardness decreased slowly for parallel polarized laser. However, the microhardness decreased rapidly for orthogonal polarized laser when the shock angle exceeded 15?. When the shock angle increased, the centeral residual stress increased first and then decreased. The residual stress hole can be solved effectively by choosing the appropriate shock angle in some cases. The conclusions can provide guidance for the laser shock peening trajectory planning of complex structures workpieces.