针对某型飞机垂尾梁误加工损伤进行了激光沉积修复研究, 根据其服役时受力特点设计了力学性能试样, 对不同沉积修复试样及同批锻件基材进行室温静载拉伸对比实验, 同时对修复试样显微组织、硬度进行分析及测试。结果表明: 沉积修复区组织为细小α/β片层组织, 无明显缺陷, 修复区与修复基体形成致密的冶金结合; 修复区至修复基体显微硬度分布呈逐步降低的趋势, 修复区显微硬度相对修复基体提高约12%; 无论修复试样标距中心是否预制孔, 修复试样室温静载抗拉强度均高于锻件基材, 但塑性比锻件基材略低; 同时, 在优化垂尾梁修复工艺参数的基础上, 对沉积修复试样侧边塌边缺陷产生的原因进行分析并给出解决措施, 以期消除塌边缺陷提高修复质量。

Researches on the laser deposition repair of aircraft vertical tail beam with mis-machined damage were investigated. According to the mechanical characteristics while its serving, the samples of mechanical properties were designed and the tensile properties at room temperature of laser deposition repaired sample and substrate sample were analyzed. Besides, microstructure characteristic, microhardness distribution were also analyzed. The results showed that there was a dense metallurgical bond between repaired zone and substrate. And the laser repaired zone experienced a continuous microstructural transition from duplex microstructure with equiaxial α and lamellar α/β in substrate to the epitaxial coarser columnar β with basket weave α/β through heat-affected zone. And the repaired zone was characterized by a fine α/β lamella microstructure without defects. Distribution of microhardness from substrate to repaired zone showed an increasing trend, and the average microhardness of repaired zone increased by 12%. Whether the tensile specimens with holes or not, laser repaired samples tensile strength were slightly higher than substrates, but the ductility were lower than substrate. Based on the optimized process parameters, the causes of edge collapse defect on the repaired sample were analyzed at the same time and the ideas to reduce defects were given to enhance the deposition quality.(LJQ2014020)