**7. Materials challenges**

A limited number of magnesium alloys are available compared to aluminum alloys. The properties can be significantly improved by introducing micro/nano-sized particles. The reinforcements offer tremendous opportunities to improve the characteristics of the material and tailored the properties. It is very difficult to avoid oxidation while handling the melt casting. Various processes need to be optimized for magnesium alloys and Mg MMCs. New forming processes should be developed to improve formability at a certain temperature and a certain strain rate.

In the hydrogen storage applications, magnesium is one of the promising candidates even though there are many available materials. But poor kinetics and high hydriding, de-hydriding temperature limits its applications. Considerable efforts are dedicated to solving these issues by preparing composites by adding catalytic materials and nanostructuring. However, Mg-based material systems still having the parameters to be optimized. It is needed that the fabrication methods for preparing sub-nano, metric crystals with size will be considered to attain the potential targets to destabilizes the strong bondage between Mg-H. Even though the targets still stay on to be experimentally achieved.

*Magnesium Alloys Structure and Properties*
