Effects of heat input on microstructure and mechanical property of Al/Ti joints by rectangular spot laser welding-brazing method

Abstract

A rectangular spot laser welding-brazing method was developed to join butted Ti/Al dissimilar alloys. In order to evaluate effects of heat input on mechanical property of the joints, microstructure of the joints were characterized. TiAl3 intermetallic compounds (IMCs) were found at the joint interface in the case of low-heat input and TiAl3, TiAl, Ti5Si3, and Ti3Al IMCs were observed at high-heat input. Results of tensile test showed that the joints fracture in the fusion zone under the condition of low-heat input and in the interfacial reaction layer or the fusion zone with a mass of porosities at high-heat input. In addition, tensile strength of specimens broken at the fusion zone is higher obviously than that at the interface or the fusion zone with a mass of porosities, and tensile strength of the joints is up to 290 MPa. © 2008 Springer-Verlag London Limited.