Researching status of dissimilar metal welding of titanium and aluminum

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.