Dissimilar material joining of Al alloy and carbon steel by center-driven double-sided linear friction welding

Abstract

Dissimilar materials A7075-T6 and S45C were joined by center-driven double-sided linear friction welding (LFW) using SUS304 as the center material. The effect of joining pressure on the joint properties was investigated, and it was found that when the joining temperature was extremely low, the joining interface could not be formed, even if sufficient deformation of both materials occurred. Upset pressure was introduced under conditions that the joining temperature was high, and it was confirmed that the joint strength increased with increasing upset pressure. The highest joint efficiency was obtained under conditions that the upset pressure exceeded the material strength of SUS304 at the joining temperature. Microscopic observations of the obtained joints revealed the absence of defects or thick intermetallic compounds at both the A7075-T6/SUS304 interface and the SUS304/S45C interface, with the presence of a thin and uniform atomic diffusion layer.