The development of high-strength flame-retardant magnesium alloys

Magnesium alloys possess a great potential for applications in the automobile and aerospace industries due to their extremely low density, exceptional machinability and enhanced dampening capacity. However, the low elastic modulus, low ductility, high flammability, and susceptibility to corrosion dramatically impeded their applications. In recent decades, some progress has been made in reinforcing magnesium alloys by alloying elements and nanoparticles to achieve higher strength and ignition points. The low melting point and low strength of magnesium alloy are their most significant drawback. The Federal Aviation Administration (FAA) of the United States lifts the ban on the use of magnesium alloys in aircraft cabins after evaluating some non-flammable magnesium alloys considering the advancement of flame-retardant magnesium alloys. Developing high flame-retardant magnesium alloys with good mechanical properties has broad prospects. The aim of this study was to comparatively review the effects of alloying elements and nanoparticles on the strength and flame retardancy of magnesium alloys and reveal the strengthening mechanism of flame retardancy. This article can offer a guideline for the compositional design of high-performance flame-retardant magnesium alloys.