Microstructure of the interface of a solid state diffusion bond between Inconel alloy 718 and 17–4 PH stainless steel

Abstract

The joining of dissimilar metals has widespread industrial applications, especially in the aerospace and nuclear industries [1]. It almost always causes changes or deterioration of the microstructure and mechanical properties of the original materials in the joint region. Solid-state diffusion bonding is a joining process in which the bond formation is the result of the interdiffusion of atoms across the bond interface. Owing to the fact that this is a solid state process, thus it does not suffer from such problems as segregation, cracking and distortion stresses generally encountered in liquid phase welding techniques [2]. In some cases the bond formation results in complete disappearance of the interface, and often 100% joint efficiencies can be achieved [3–5]. Diffusion bonding has emerged as a potential joining process for making precision joints between dissimilar metals.