Effect of pulsed current on interfacial microstructure during welding-brazing of Ti/Al dissimilar alloys

Butt joining of titanium alloy to aluminum alloy Al2024 was conducted using pulsed current gas tungsten arc welding. The influence of pulsed current on Ti/Al interfacial microstructure was studied. The microstructure of Ti/Al interface with different locations were investigated along the depth direction of joint. Element distribution cross the interface was analyzed by EDS. Phase constituent near the interface were determined by XRD. The results indicated that Ti/Al dissimilar alloys were successfully joined using pulsed current gas tungsten arc welding. Titanium was partially melted during welding and a welded-brazed joint was formed. Distribution of welding heat input was improved by the addition of pulsed current. Difference of Ti/Al interface along the thickness direction was mitigated. Formation of continuous brittle intermetallic compound was restricted to a low level due to the effect of pulsed current. Cracking sensitivity of the joint was decreased and performance of the joint was increased.