Cold metal transfer welding of dissimilar metals between 6061 aluminum alloy and TA2

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.