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基于连续激光冲击强化7050铝合金中厚板的表面完整性和内部层裂,提出了一种激光冲击强化的过喷效应.7050铝合金中厚板尺寸为50 mm×50 mm×5 mm(长×宽×高).激光工艺参数为激光能量30J,光斑尺寸4mm×4 mm,脉宽15 ns和单点连续多次激光冲击(LSP-1～LSP-8).表面形貌,表面残余应力,深度方向显微硬度和截面微观组织分别用超景深三维形貌仪,X射线衍射仪,显微硬度仪和金相显微镜测试分析.研究结果表明:单点连续5次激光冲击诱导7050铝合金中厚板表面微凹坑凸起高度为197.8 μm和山脊高度为130.8 μm.从单点连续4次激光冲击到单点连续5次激光冲击,试样表面残余应力由压应力转换为拉应力.单点连续5次激光冲击后,试样背层产生了低显微硬度的加工软化现象.单点连续5次激光冲击为7050铝合金中厚板的层裂阈值.研究结果有益于激光冲击强化工业应用中避免层裂和改善强化效果.“,”An over peening effect was presented based on the researches of surface integrity and internal spall of Al7050 mid-thick plates with continued multiple laser shock peening (LSP) impacts at the same position.The dimensions of the samples were 50 mm×50 mm×5 mm (length×width×thickness).Laser process parameters were laser energy of 30 J,square spots of 4 mm×4 mm,pulse width of 15 ns and continued multiple LSP impacts at the same position (LSP-1～LSP-8).Surface morphology,surface residual stress,and micro-hardness in depth and cross-sectional microstructure were measured by super depth 3D microscope system,X-ray diffraction instrument,Vickers indenter and optical microscope (OM),respectively.The results indicate that high micro-dent depressions of 197.8 μm and ridges of 130.8 μm are generated after continued LSP-5.Surface compressive residual stress changes into tensile residual stress from continued LSP-4 to continued LSP-5.After continued LSP-5,work softing with low micro-hardness is found in the bottom layer.Continued LSP-5 is the spall threshold of Al7050 mid-thick plates.The research is beneficial to avoid the spall and improve the strengthening effect in the industry application of LSP.