以低氧TC4粉末为熔覆材料,采用激光修复技术制备了TC4钛合金面修复试样,对比研究了锻件和修复试样(沉积态)的显微组织和力学性能。结果显示:修复试样的组织宏观上分为锻件基材区、热影响区和激光沉积区,3个区域中热影响区的显微硬度最高,沉积区和锻件基材的显微硬度相当。锻件试样的强度及塑性均略高于修复试样,同时发现40%修复试样(即拉伸试样承受载荷部位横截面上沉积区所占的面积分数为40%)的强度略低于50%修复试样,塑性则高于后者。表明采用低氧TC4粉末为熔覆材料时,有利于修复试样沉积区和基材区强度和塑性的匹配,从而提高修复试样的综合性能。对拉伸断口进行扫描电镜观察发现,锻件试样拉伸失效后断口呈现出典型的韧性断裂特征,而修复试样的断口则表现复杂,从沉积区到锻件基材区呈现出解理台阶到韧窝的连续变化特征,同时断口形貌与显微组织呈现出很好的对应关系。 Using TC4 powder as cladding material, the TC4 titanium alloy surface repair sample was prepared by laser repairing technique. The microstructure and mechanical properties of the forging and repaired sample were compared. The results show that the microstructure of the repaired sample is macroscopically divided into the forging substrate area, the heat affected zone and the laser deposition area. The microhardness of the heat affected zone in the three areas is the highest, and the microhardness of the substrate in the deposition area and the forging substrate is equivalent. The strength and ductility of the forged specimens were slightly higher than that of the repaired specimens and the strength of 40% of the repaired specimens (ie, the area occupied by the deposition area on the cross-section of the tensile specimen was 40%) was slightly lower than the strength 50% repair the sample, the plastic is higher than the latter. It shows that the use of low-oxygen TC4 powder as the cladding material is conducive to repair the matching of the strength and the plasticity of the deposition area and the substrate area of ​​the sample, so as to improve the comprehensive performance of the repaired sample. The scanning electron microscopic observation of the tensile fracture shows that the fracture shows a typical ductile fracture characteristic after the tensile failure of the forging specimen, and the fracture of the repaired sample is complicated. From the deposition area to the forging substrate area, Dimple continuous changes in the characteristics of the same time, fracture morphology and microstructure showed a good correspondence between.