钛合金与铝合金异种金属焊接的研究现状

Researching status of dissimilar metal welding of titanium and aluminum

对钛/铝异种金属焊接过程中脆性Ti-Al金属间化合物的控制方法进行了综述,介绍了熔化焊(激光焊、电子束焊)、钎焊、熔钎焊、扩散焊、搅拌摩擦焊及爆炸焊的研究现状,并对存在的问题与发展趋势进行了讨论。结果表明,钛/铝焊缝中极易形成脆性的Ti-Al金属间化合物,导致钛/铝接头强度的降低。在激光焊、电子束焊过程中,通过热源偏移的方式可以降低Ti-Al金属间化合物含量;采用合理的中间层,既能降低Ti-Al金属间化合物的含量又能形成塑性更好的金属间化合物。采用熔钎焊工艺并选用合适的填充材料,可以有效地抑制Ti-Al金属间化合物的生成。采用扩散焊工艺、通过添加中间层、在钛表面渗铝及合理控制工艺参数,能有效减少Ti-Al脆性金属间化合物的生成,但接头的抗拉强度不高。采用搅拌摩擦焊并通过添加中间层抑制钛/铝接头中Ti-Al脆性金属间化合物的形成,获得性能良好的钛/铝接头,但会受到焊件的形状的影响。采用爆炸焊工艺,可以细化界面中的金属颗粒,提高钛/铝接头的强度。

Control methods of brittle Ti-Al intermetallic compounds in welding process of titanium/aluminum dissimilar metals were reviewed.Research status of fusion welding(laser welding,electron beam welding),brazing,welding-brazing,diffusion welding,friction stir welding and explosion welding were introduced,and the existing problems and development trend were discussed.The results showed that brittle Ti-Al intermetallic compounds were easily formed in titanium/aluminum welded joints,which resulted in a decrease in the strength of titanium/aluminum joint.In the process of laser welding and electron beam welding,the content of Ti-Al intermetallic compounds could be reduced by means of heat source migration.By adopting welding-brazing process and reasonable interlayer,not only the content of Ti-Al intermetallics was reduced,but also intermetallics with better plasticity were formed.The formation of brittle Ti-Al intermetallic compounds could be effectively reduced by diffusion welding process,adding intermediate layer,aluminizing on titanium surface and reasonable control of technological parameters,but tensile strength of the joint was not high.The titanium/aluminum joints with good performance were obtained by adding interlayer in friction stir welding to suppress the formation of brittle Ti-Al intermetallic compounds in titanium/aluminum joints,but which was affected by the shape of weldment.Metal particles in the interface were refined to improve strength of titanium/aluminum joint by explosive welding technology.