Hydrogen desorption properties of MgH2-5 at% Ni3FeMn composite via combined vacuum arc remelting and mechanical alloying

Document Type: Original Paper


Department of Material Science and Engineering, Faculty of Mechanical Engineering, Babol Noshirvani University of Technology, P.O.Box 47148-71167, Shariati Street, Babol, Iran


In this study, the composite material with composition of MgH2-5 at% Ni3FeMn has been prepared by co-milling of MgH2 powder with Ni3FeMn alloy. 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. It has been shown that addition of 5 at% Ni3FeMn to MgH2 and mechanical alloying (MA) up to 30 h formed a nanocrystalline composite with the average crystallite size of MgH2 of 17 nm and average particle size of 1.4 µm. As a consequence, the desorption temperature of composite material milled for 30 h has decreased from 421 °C to 307 °C. Furthermore, the dehydrogenation has started at ~ 140 °C after 30 h MA, revealing catalytic effect of Ni3FeMn alloy.