Interfacial reaction mode and its influence on tensile strength in laser joining Al alloy to Ti alloy

Abstract

In order to obtain a robust dissimilar joint of Al/Ti alloys, a filler wire of Al–12 wt-%Si and 45° V shape groove on the base metal were used during CO₂ laser welding. Heat input had evident influence on the interfacial reaction mode. It was found that a dissolution mode for low heat input and a melting mode for high heat input exist at the joint interface, which was analysed from thermodynamic point of view. Tensile strength of the joints in the dissolution mode reached as high as 296 MPa, which was significantly higher than that in the melting mode.