GIL壳体5754铝合金FSW与GTAW接头组织和性能

Microstructure and mechanical properties of 5754 aluminum alloy FSW and GTAW welded joints

针对GIL壳体材料5754铝合金,制备FSW和GTAW接头,并研究焊接接头的显微组织、拉伸性能、弯曲性能和冲击性能。结果表明,两种焊接方法下焊缝组织均为α-Al基体弥散分布着细小的β相(Al8Mg5),采用GTAW方法时,热影响区晶粒明显粗化;两种焊接接头的强度和弯曲性能均可以满足壳体的强度设计要求。由于FSW过程的搅拌作用,焊缝金属发生高温动态回复再结晶,因此FSW接头的抗拉强度和冲击性能更为优异。

For 5754 aluminum alloy employed in GIL,FSW and GTAW processes were adopted,and the microstructure,tensile properties,bending properties and impact properties of the welded joints were analyzed. The welded joints contained the matrix phase α-Al and the dispersed second β phase( Al8 Mg5) in two welded joints,and the grains in the heat affected zone are obviously coarsening in GTAW joint. The tensile and bending properties of both welded joints meet the GIL shell requirements of mechanical properties. Due to the dynamic recovery and recrystallization in FSW method,the FSW joints are higher in tensile and impact properties.