A review on dissimilar metals’ welding methods and mechanisms with interlayer

The study of dissimilar metals’ welding is an important issue due to their increasing applications in many industrial fields. Welding of dissimilar metals is challenging because of the formation of large residual stress and brittle intermetallic compounds (IMCs). In order to solve this problem, intermediate interlayers were used to eliminate or inhibit the formation of brittle intermetallic reaction layers in many welding techniques, such as diffusion bonding, laser welding, electron beam welding, and other welding techniques. The aim of this paper is to review the recent progress of dissimilar metals’ welding methods and mechanisms with interlayer to offer a basis for the following research. The work discussed several criteria for the selection of interlayer, such as physical properties, metallurgical compatibility, mode, and thickness of the interlayer. Then, formation enthalpy, Gibbs energy of formation (Δ G ), and brittleness of the IMCs, as well as welding parameters, were also discussed. Simultaneously, the present work had proposed a design guideline for the selection of interlayer in dissimilar metals’ welding to acquire a welded joint with good quality.