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用手工氩弧焊,ER5356焊丝对2A12铝合金板进行了焊接,采用超声冲击处理技术对焊接接头进行了全覆盖超声冲击处理;通过金相显微镜、扫描电镜和单向拉伸试验对处理和未处理的接头组织和力学性能进行了测试和观察分析,研究了超声冲击处理提高铝合金焊接接头强度和韧性的机理。结果表明:与未处理试样相比,超声冲击处理试样的抗拉强度提高了17.4%,伸长率增加了28%;未经超声冲击处理的2A12铝合金焊接接头断裂均发生在焊趾和熔合区,处理后断口均在焊缝中部断面,并在强化层处发生45°转折。超声冲击处理形成的塑性变形层和晶粒细化,以及降低接头表层气孔、缩松等焊接缺陷的作用是其改善焊接接头力学性能的主要原因。
The 2A12 aluminum alloy plate was welded with ER5356 welding wire by manual argon arc welding. The ultrasonic welding technology was used to treat the welded joints with full coverage ultrasonic impact treatment. The microstructure, The mechanical and mechanical properties of the welded joint were tested and observed. The mechanism of ultrasonic impact treatment to improve the strength and toughness of the welded joint of aluminum alloy was studied. The results show that compared with the untreated sample, the tensile strength of the sample by ultrasonic impacting is increased by 17.4% and the elongation is increased by 28%. The fracture of 2A12 aluminum alloy without ultrasonic impacting occurs on the weld toe And the fusion zone, the fractures are all in the middle section of the weld after the treatment, and a 45 ° turning occurred in the strengthening layer. The main reason of improving the mechanical properties of welded joints is the plastic deformation layer formed by ultrasonic impact treatment and grain refinement, as well as the effect of reducing welding defects such as stomata and shrinkage on the joint surface.