Characteristics of aluminum-to-steel joint made by friction stir welding: A review

Friction stir welding exploits its solid state process behaviour to join aluminum to steel, which differs in thermal and mechanical properties, and where combination of these metallic alloys by fusion welding prompts a deleterious reaction as a result of the melting and resolidification phases. This review investigates the distinction and characterization of aluminum to steel joints made by this welding method. An attempt to address sub -techniques into three categories i.e., diffusion, plunging, and annealing, is made. Steel fragments spattered at the weld zone, weld defects, sharp difference in grain size distribution, and the formed phases of the intermetallic layer and its thickness are discussed, these factors and the process welding parameters are significantly influenced the joint's strength of this welding method. (C) 2015 Elsevier Ltd. All rights reserved.