Al6061/TA2异种金属冷金属过渡焊接性分析
Cold metal transfer welding of dissimilar metals between 6061 aluminum alloy and TA2
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摘要: 以AlSi5 焊丝对6061铝合金和TA2纯钛进行CMT熔钎焊,采用SEM,EDS分析焊接接头的微观组织特征,并通过拉伸试验对接头进行力学性能评定.结果表明,焊接过程稳定,焊缝成形美观.所得到的焊接接头具有熔焊和钎焊两部分,其中局部熔化的铝母材与熔融的焊丝混合后形成焊缝,焊缝金属与微熔的钛母材形成三个钎焊界面.钎焊界面主要成分为TiAl3金属间化合物,其厚度较薄.此外,界面附近还有一些随机分布的棒状的TiAl3金属间化合物.焊接过程中,随着焊丝偏移量的增加,焊缝力学性能提高.参数优化后的接头抗拉强度较高,且断裂在铝热影响区.Abstract: CMT fusion-brazing of 6061 aluminum alloy to TA2 pure titanium sheets was carried out using AlSi5 filler wire.The microstructure of the resultant Ti/Al joints was analyzed with SEM and EDS.The mechanical properties of the joints were characterized by measuring the tensile strength.The results indicate that the welding process was stable and desired welding appearance was achieved.The fusion-brazed joints could be formed,which included a fusion-welded joint on aluminum side and a brazed joint on titanium side.Three thin brazed interfaces were mainly composed of TiAl3.In addition,some rod-like TiAl3 phases was found near the brazed interface.The tensile strength of the joints increased with the increase of the deviation distance of the filler wire.The joints with optimized welding parameters had high tensile strength and fractured in the heat-affected zone (HAZ) on aluminum side.