中文摘要：

使用特定的搅拌摩擦焊工艺参数焊接7N01铝合金试板,得到有孔洞缺陷的接头,并对原始缺陷接头进行搅拌摩擦焊一次补焊和二次补焊。试验结果表明,搅拌摩擦焊补焊可以修复原始接头的孔洞缺陷。补焊后,焊核区晶粒尺寸略有减小,同时晶粒尺寸不均匀性增加,后退侧热机影响区晶粒有再结晶现象;补焊接头显微硬度较原始缺陷接头下降3～5 HV,一次补焊接头屈服强度和抗拉强度较原始接头分别提升了81.7和166.4 MPa。二次补焊接头力学性能较一次补焊接头又略有下降,焊缝表面下凹逐渐严重。

英文摘要：

The 7N01 aluminum alloy plates were welded by using specific frition stir welding process parameters to get joints with hole defect, and then the first and the second repair welding of the original defective joint were carded out by using friction stir welding . The test results show that the original joint with hole defect can be repaired by friction stir repair welding. After the repair welding, the grain size in nugget zone decreases slightly, the inhomogeneity of grain size increases, and the grain in the thermo-mechanically affected zone at retreating side presents recrystallization phenomenon. Compared with the original defective joint, the hardness of the repair welding joint decreases 3-5 HV, and the yield strength and tensile strength of the first repair welding joint incease 81.7 and 166.4 MPa respectively. The mechanical properties of the second repair welding joint decrease slightly compared with that of the first repair welding joint, and the lower concave phenomenon of the weld surface is gradually serious.