为了提高镁合金航空构件修复质量、延长服役寿命，本工作针对航空镁合金构件的冶金缺陷及服役损伤开展了ZM6合金激光沉积修复研究，对比分析了固溶时效(T6：520 ℃、8 h + 220 ℃、14 h)处理前后修复试样微观组织及力学性能的变化。结果表明，沉积态试样修复区组织由细小的α-Mg相和第二相组成，第二相主要以连续网状分布在晶界处，少量以点状及棒状分布在晶粒内部。修复区平均硬度为(60 ± 2) HV_0.1，修复试样的抗拉强度、屈服强度和延伸率分别为137.47 MPa、111.61 MPa和5.57%，其断裂位置在基材部分，断裂模式为沿晶-穿晶混合的脆性断裂；经T6处理后，修复区组织由细小的α-Mg晶粒和异常粗大晶粒组成，且晶粒内部析出了β′相。T6处理后试样修复区的平均硬度提高17.5%，异常粗大晶粒和细小晶粒导致硬度波动范围较大，抗拉强度和屈服强度分别提升了49.8%和75.6%，但延伸率有所下降。拉伸试样断裂位置在修复区，异常粗大晶粒是引起断裂的主要原因。

ZM6 (Mg-Nd-Zn-Zr) alloy is a typical casting magnesium alloy with low density, high specific strength and stiffness, good vibration damping performance, good machinability, and good heat resistance. It is widely used in aerospace and aviation fields. However, metallurgical or machining defects are inevitable while processing due to the complicated shapes and large scales of aviation components. Failure to repair them may lead to significant economic loss. Laser deposition repair can be applied to aerospace components because of the advantages of small heat input and high molding accuracy. This work focuses on repairing the aerospace ZM6 magnesium alloy components using laser deposition, addressing the metallurgical defects and service damage to the components. The changes in the microstructure and mechanical properties of the repaired ZM6 samples before and after solution aging (T6: 520 ^oC, 8 h + 220 ^oC, 14 h) treatment were compared. The results show that the microstructure of the repaired zone of the as-deposited sample consists of fine α-Mg grains. The secondary phases distributed mainly at grain boundaries showed a continuous network, and a small number of the dot- and rod-shaped secondary phases were distributed inside Mg grains. The average hardness of the repaired zone is (60 ± 2) HV_0.1, and the tensile strength, yield strength, and elongation were 137.47 MPa, 111.61 MPa, and 5.57%, respectively. The fracture occurred in the base metal, and the tensile fracture mode comprised transgranular and intergranular brittle fractures. After T6 treatment, the microstructure of the repaired zone comprised fine α-Mg grains and abnormally coarse grains, and β′ phase was precipitated inside the grains. The average hardness of the repaired zone increased by 17.5% compared to that of the as-deposited samples, and the abnormally coarse and fine grains led to various hardness fluctuations. The tensile strength and yield strength of the T6-treated samples increased by 49.8% and 75.6%, respectively, but the elongation decreased. The fracture location of the tensile sample was in the repaired zone because of the formation of abnormally coarse grains.