以2219-T87铝合金为塞棒材料，采用摩擦塞补焊工艺对8 mm厚7075-T651铝合金进行焊接，并对不同工艺参数下接头的成形、微观组织、力学性能等进行观察和测试.结果表明，采用优化的工艺参数可以获得无缺陷的接头，塞棒和母材摩擦界面形成了等轴晶.根据组织形貌可以把摩擦塞补焊接头分成再结晶区、热力影响区、塞棒热力影响区、热影响区、塞棒热影响区和母材6个区，热力影响区组织发生了变形和长大以及沉淀相的溶解和粗化，局部发生了软化，尤其是塞棒热力影响区硬度值最低，在90 ~ 95 HV左右，拉伸试验时无缺陷的接头断裂位置在塞棒区，断裂模式为韧性特征. 摩擦塞补焊接头抗拉强度最高可达343 MPa，断后伸长率最高达7.0%，分别达到母材的63.8%和77.8%.
Friction plug welding (FPW) for 8 mm thickness 7075-T651 aluminum alloy sheets were carried out using 2219-T87 aluminum alloy as plug material, and the formation and microstructure characteristics of the FPW joints obtained by using different process were observed, and the properties were tested. The results show that defect-free joints can be obtained with optimized parameters, and equiaxed grains were formed at the friction interface between the plug and base material. According to the structure and morphology, the FPW joint can be divided into 6 zones: recrystallization zone, thermo-mechanical affected zone, plug thermo-mechanical affected zone, heat affected zone, plug heat affected zone and base metal. The microstructure of the thermo-mechanical affected zone grew and deformed, with the precipitation phase dissolved and coarsened. Local softening also occurred. In particular, the hardness value of the plug heat affected zone reached the lowest at about 90 ? 95 HV. During the tensile test, fracture of the defect-free FPW joint happened at the plug center, with ductile features in terms of fracture mode. The maximum tensile strength and elongation of the FPW joints reached 343 MPa and 7.0%, reaching 63.8% and 77.8% of that of the base metal, respectively.
[1] Li Xiaoping, Liu Xiao, Li Runzhou, et al. Microstructure and property research on welded joints of 7xxx aluminum alloy welding wire TIG for 7075 aluminum alloy[J]. China Welding, 2021, 30(4): 58-64.
[2] 张允康, 许晓静, 罗勇, 等. 7075 铝合金强化固溶T76处理后的拉伸与剥落腐蚀性能[J]. 稀有金属材料与工程, 2012, 41(S2): 612-615
Zhang Yunkang, Xu Xiaojing, Luo Yong, et al. Tensile property and exfoliation corrosion of 7075 aluminum alloy after enhanced-solid-solution and T76 aging treatment[J]. Rare Metal Materials and Engineering, 2012, 41(S2): 612-615
[3] Tian J, Li J P, Bai Y P, et al. Effect of equal channel angular pressing on microstructure and mechanical properties of 7075 aluminum alloy[J]. Transactions of Materials and Heat Treatment, 2016, 37(7): 61-68.
[4] Wang G, Zhao Y, Hao Y. Friction stir welding of high strength aerospace aluminum alloy and application in rocket tank manufacturing[J]. Journal of Materials Science & Technology, 2018, 34(1): 73-91.
[5] Nandan R, DebRoy T, Bhadeshia H K D H. Recent advances in friction stir welding: process, weldment structure and properties[J]. Progress in Materials Science, 2008, 53(6): 980-1023.
[6] 孙转平, 杨新岐, 杜波, 等. 2219 铝合金FSW 焊缝摩擦塞补焊接头性能分析[J]. 焊接学报, 2019, 40(5): 143-147
Sun Zhuanping, Yang Xinqi, Du Bo, et al. Investigation on mechanical properties of friction plug welded joints for 2219 friction stir welds[J]. Transactions of the China Welding Institution, 2019, 40(5): 143-147
[7] Sun Zhuanping, Yang Xinqi, Li Shuxin. Characteristics of friction plug joints for AA2219-T87 FSW welds[J]. Materials, 2022, 15(4): 1-17.
[8] 孙转平, 杨新岐, 刘凯旋, 等. 异种铝合金摩擦塞补焊工艺与组织性能[J]. 焊接学报, 2019, 40(9): 145-150
Sun Zhuanping, Yang Xinqi, Liu Kaixuan, et al. Study of technology and structure property on friction plug welding of dissimilar aluminum alloy[J]. Transactions of the China Welding Institution, 2019, 40(9): 145-150
[9] Du Bo, Cui Lei, Yang Xinqi, et al. Weakening mechanism and tensile fracture behavior of AA2219-T87 friction plug welds[J]. Materials Science & Engineering: A, 2017, 693: 129-135.
[10] 杜波, 孙转平, 杨新岐, 等. 异种铝合金摩擦塞补焊接头微观组织及性能[J]. 机械工程学报, 2017, 53(4): 44-48
Du Bo, Sun Zhuanping, Yang Xinqi, et al. Microstructures and properties of friction stir welded aluminum alloy[J]. Journal of Mechanical Engineering, 2017, 53(4): 44-48
[11] Dalder E C, Pastrnak J W, Engel J, et al. Bobbin-tool friction-stir welding of thick-walled aluminum alloy pressure vessels[J]. Welding Journal, 2007, 87(4): 1-17.
[12] Hartley P J. Friction plug weld repair for the space shuttle external tank[J]. Welding & Metal Fabrication, 2002, 9: 6-8.
