摘要
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。
Aluminum alloy 2A12 was TIG welded using ER5356 welding wire.The welded joint was strengthened by ultrasonic impact treatment（UIT）.The mechanical behavior and microstructure of the welded joint with and without UIT were studied by means of tensile test,optical microscopy and scanning electron microscopy.The strengthening mechanism of UIT on 2A12 aluminum alloy weld joint were discussed.Results show that tensile strength and elongation of the welded joint after UIT increase about 17.4% and 28%,respectively.The welded joints without UIT are fractured in the weld toe and fusion zone,while those with UIT are cracked in the center of the welding bead and present a 45° turning of the cracking path in the strengthened surface layer.The plastic deformation,grain refinement and reduction of welding defects in the welded joints after UIT are the main mechanisms for the improvement of mechanical properties of the 2A12 aluminum alloy welded joint.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2010年第7期104-108,共5页
Transactions of Materials and Heat Treatment
基金
北京市自然科学基金资助项目(No.3093027)
关键词
铝合金
超声冲击
焊接接头
拉伸强度
伸长率
aluminum alloy
ultrasonic impact treatment
welded joint
tensile strength
elongation
