Research progress and future prospects on high speed extrudable magnesium alloys: A review

Magnesium (Mg) and its alloys, as the lightest metal structural materials, are significantly attractive for lightweight applications. However, the extrudability of commercial Mg alloys is obviously poor compared with Al alloys, which has greatly restricted their widespread application so far. To further expand the industry uptake of Mg alloy extrusion components, development of the low-cost, high speed extrudable Mg alloys with good mechanical performance is strongly desired. In this review, the factors determining the extrudability of Mg alloys are critically analysed. Besides, recent research highlights on high speed extrudable Mg alloys are systematically reviewed from the perspective of the alloying systems, specifically focusing on Mg–Al, Mg–Zn, Mg–Sn, Mg–Bi and Mg–RE based alloys. Furthermore, the new alloy design concepts and novel extrusion processing routes are critically analysed and summarized, and also the recommendations for future research prospects for high speed extrudable Mg alloys are also suggested. We hope this review will inspire new ideas on both composition design and technology innovation for developing high speed extrudable Mg alloys with excellent strength-ductility synergy.