Macro-/micro-structures and mechanical properties of magnesium alloys based on additive manufacturing: a review

Additive manufactured (AM) technology as a novel fabrication method provides an unprecedented ability to completely design parts freely and breaks through the limitations of traditional approaches to manufacture complex structural parts. Meanwhile, magnesium (Mg) and its alloys as the lightest structural metal materials are among the most promising materials and always catch research attention. The combination of AM and Mg alloys would certainly provide new impetus for the practical application of Mg alloys. Although the research of AM-Mg alloys has made some progress and some AM-Mg alloys with impressive properties have been developed, there are still some intractable issues that hinder the further development and application of AM-Mg alloys. This paper provides a short review of the recent progress achieved in AM-Mg alloys, with a specific focus on selective laser melting (SLM), wire-arc additive manufacturing (WAAM), and solid-state AM technologies including additive friction stir (AFS) and friction stir additive manufacturing (FSAM). The defects, microstructure, and mechanical properties of AM-Mg products are summarized based on the type of AM technique. Besides, the effect of post-treatment on macro- and microstructures of SLM-Mg and WAAM-Mg alloys is also summarized. In addition, further perspectives and potential research directions are proposed for the development of AM-Mg alloys. This review could provide insights into the development of AM-Mg alloys with enhanced mechanical properties and promote the application of AM-Mg alloys.