不同焊接工艺下2219铝合金TIG焊接头性能分析

针对2219铝合金的对接TIG焊，采用单面两层焊和两面三层焊的工艺方法开展了对比试验，分析了焊接接头形貌和组织性能。研究结果表明，两种工艺方法均可以获得良好的焊缝成形，力学性能满足结构设计要求；两面三层焊比单面两层焊的焊接接头抗拉强度和断后伸长率的平均值分别提高了1.7%和33.3%，抗拉强度基本相同，断后伸长率得到了大幅提升；相比于单面两层焊，两面三层焊的背部封底焊接增加了背部焊缝宽度，背部熔合线的形状以及与水平方向的夹角都发生了变化；两种工艺方法的焊接接头各区域组织特点鲜明，相同区域的微观形貌相差不大；在焊缝背部相同位置，两种工艺方法的硬度值曲线走向趋势相同，封底焊增大了过时效软化区的宽度，提高了焊接接头的断后伸长率。

Performance analysis of 2219 aluminum alloy TIG welded joints under different welding processes

For TIG butt welding of 2219 aluminum alloy,the single-sided two-layer welding process and two-sided three-layer welding process were used to carry out comparative tests,and the shape and microstructures of the welded joints were analyzed. The results show that both methods can obtain well appearance of weld,and the mechanical properties meet the structural design requirements. Compared with the oneside two-layer welded joint,the average value of the tensile strength and elongation of the welded joint fabricated by the two-sided three-layer welding increases by 1. 7% and 33. 3%,respectively. The tensile strength is basically the same and the elongation is greatly improved. Compared to the single-sided two-layer welding,the back sealing of the two-sided three-layer welding increases the width of the back weld,the shape of the back fusion line and the angle between the back fuse line and the horizontal direction have changed. The microstructures of the welded joints of the two methods are distinct,and the microstructures of the same area are not much different. At the same position on the back of the weld,the hardness values of the two processes have the same trend,and the back sealing weld increases the width of the overage soften-ing zone,which makes the elongation of the welded joint increase.