Weldability of Aluminum-Steel Joints Using Continuous Drive Friction Welding Process, Without the Presence of Intermetallic Compounds

Abstract

Weldability of aluminum-steel joints has been studied mainly to avoid the formation of IMC. Nowadays, there are two ways to control the effect of Fe_xAl_y in welding: 1) the elimination of IMCs or 2) the generation of a thin and homogeneous layer of these phases. In this way, the present work explores the first route, manufacturing joints aluminum-steel using solid state welding process. In order to evaluate the effect of the welding parameters, temperature measures were carried out during the process as well as the microstructural evaluation using optical microscopy and SEM. Finally, the welded joints were subject to tensile strength tests to evaluate their mechanical behavior and try to stablish the nature of the interfacial bonding between both metals. The microstructural characterization of the joints does not reveal the formation of IMCs; this is attributed to the low temperature reached during the process, lower than 545 °C. The welded joint failures in the TMAZ, in the low hardness zone, product of the over aging of the precipitates β”. The nature of the bonding in the interface is not clear yet, but it is considered that the atomic diffusion trough the interface favors the joint formation