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设计了针对7075铝合金搅拌摩擦焊接头的焊后双温固溶处理/时效的热处理制度,并采用扫描电镜,透射电镜,显微硬度和拉伸试验研究了双温固溶处理对搅拌摩擦焊7075铝合金接头组织及性能的影响。结果表明,双温固溶处理可以实现接头组织的充分均匀化,同时导致粗大MgZn_2析出相的部分溶解和细小的MgAlCu相析出。经双温固溶处理和130℃时效处理24 h后,接头力学性能明显恢复,焊接区硬度高于母材,接头强度和塑性与母材相当。
The heat treatment system of 7075 aluminum alloy friction stir welded joint after dual-temperature solution treatment / aging was designed. The effect of dual-temperature solution treatment on friction stir welding was studied by scanning electron microscopy, transmission electron microscopy, microhardness test and tensile test. Effect of the Structure and Properties of 7075 Aluminum Alloy Joints. The results show that the solution treatment at two temperatures can achieve sufficient homogenization of the joint structure, and lead to the partial dissolution of the coarse MgZn 2 precipitates and the precipitation of the fine MgAlCu phase. The mechanical properties of the joint recovered obviously after the solution treatment at both temperature and the aging treatment at 130 ℃ for 24 h, the hardness of the weld zone was higher than that of the base metal, and the strength and plasticity of the joint were comparable with the base metal.