2219铝合金FSW焊缝摩擦塞补焊接头性能分析

采用顶锻式摩擦塞补焊方法，对8 mm厚2219-T87铝合金FSW焊缝进行了摩擦塞补焊试验研究，深入探讨摩擦塞补焊接头的微观组织、常温和低温力学性能、硬度及断口形貌变化特征. 结果表明，摩擦塞补焊接头具有明显的组织不均匀性，主要由塞棒区、塞棒热力影响区、再结晶区、母材热力影响区、热影响区和母材区组成；母材热力影响区晶粒具有显著变形特征, 其硬度最低为85 HV，是整个接头的薄弱部分. 摩擦塞补焊接头的常温和低温抗拉强度均达到FSW接头的80%以上，断后伸长率达到70%以上，其断裂模式为韧性特征.

Investigation on mechanical properties of friction plug welded joints for 2219 friction stir welds

Based on the friction push plug welding method, the investigations of friction plug welding experiments for 2219-T87 friction stir welds with 8 mm thickness by using the 2219-T6 plugs have been performed. The varying features of microstructures, mechanical properties at room, low temperature conditions, micro-hardness profiles and fracture modes have been analyzed in details. The results show that the microstructures of FPW joints was obviously inhomogeneous. The joints are mainly composed of plug zone, plug thermo-mechanical affected zone, recrystallization zone, base metal thermo-mechanical affected zone, heat affected zone and base material. The grains in the thermo-mechanically affected zone of base metal is the weakest areas of whole FPW joints at which the grains have the obviously deformed features and the lowest micro-hardness of 85 HV, which are the tensile strength of FPW joints at room and low temperatures can reach above 80% of FSW joint, the elongation can reach above 70%, and the fracture modes of FPW joints are possessed of ductile features.