Hydrogen desorption properties of nanocrystalline MgH2-5 wt% SiC composite synthesized by mechanical alloying

In this study, the composite material with composition of MgH2-5 wt% SiC has been prepared by co-milling of MgH2 with SiC powder. The effect of milling time and additive on the hydrogen desorption properties of obtained composite was evaluated by thermal analyzer method and compared with pure un-milled MgH2. The phase constituents and grain size of powder were characterized by X-ray diffractometry method. It has been shown that addition of 5 wt% SiC to MgH2 and mechanical alloying up to 30 h formed a nanocrystalline composite with the average crystallite size of 12 nm and average particle size of 0.5 μm. As a consequence, the desorption temperature of composite material milled for 30 h has decreased from 435 °C to 361 °C.

Keywords:

Magnesium hydride , Mechanical alloying , Hydrogen desorption temperature , SiC addition