采用激光沉积修复技术修复预制槽损伤拉伸试样，通过光学显微镜和扫描电子显微镜对修复试件的显微组织、拉伸断口及断口附近变形组织进行分析观察。结果表明,修复区组织由Al枝晶和枝晶间Al-Si共晶组成，Si相呈珊瑚状形貌；修复占比为10%和20%的试件的室温抗拉强度分别达到了铸件标准的90%和88%，断后伸长率均优于铸件标准；基材区断裂机制为脆性断裂，而修复区为韧性断裂；基材区微裂纹断裂方式为穿晶断裂，而修复区为沿晶断裂。

The laser deposition repair technology is used to repair the tensile specimen with pre-damage and the microstructure, tensile fracture and its neighboring deformation structure are examined and analyzed by the optical microscope and scanning electric microscope. The results show that the microstructure at repaired zone is composed of Al dendrites and Al-Si eutectic whose Si-phase presents Coral-like morphology. The tensile strengths at room temperature of specimens with repair-ratios of 10% and 20% can reach up to 90% and 88% of the casting standard and their elongation rates are both superior to the casting standard; the fracture mechanism at substrate zone is brittle-fracture type, while that at repair zone is ductile-fracture type; the fracture mode for micro-fractures at substrate zone is transgranular, while that at repair zone is granular.