The paper critically assesses the research progress towards aluminium–magnesium dissimilar friction stir welding (FSW). First, the theoretical requirements are explored through the understanding of joining mechanism and heat generation in aluminium–magnesium FSW. Next, the observed trends in microstructural characterisation and mechanical properties are analysed. Finally, the effects of welding parameters and how it influences process variables and materials responses are discussed in detail, and several suggestions are made based on these discussions.

This paper presents a review of research progress on aluminum–steel dissimilar welding. Current issues and recent developments in improving the intermetallic compound layer of weld joint are critically assessed. Several welding factors that improve joint quality, such as welding method, weld and material preparations, as well as welding parameters, are also discussed. This study also examines recent developments in hybrid welding techniques and proposes a preheating method to enhance the weld joints of aluminum–steel dissimilar welding.