LAUSR

Abstract A sound Ti/Al butt joint was successfully obtained by dual-spot laser welding–brazing with a Al-12Si wire as the filler. The influence of laser power on the weld appearance, microstructure of the interfacial intermetallic compounds (IMC), and tensile strength of joints was investigated. With an increase in laser power, the thickness of IMC layer also increased and the morphology of IMC layer changed from a cellular-shape to a serrated-shape, and finally to a club-shape. The microstructure of the interface IMC comprised a brazed zone in which Ti(Al, Si)3 was dominant and the microstructure at the Ti/Ti(Al, Si)3 interface was composed of nano-sized granular Ti5Si3, and Ti7Al5Si12. The highest tensile strength of the joints could reach up 75% of that of the Al base metal. The inhomogeneous IMC layer at the brazing interface caused a decrease in the tensile strength of joints and induced a deflection of fracture path during the tensile process.