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

Motavalli, Ali; Rajabi, Mohammad

doi:10.22075/ancr.2014.172

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

Document Type : Original Paper

Authors

Ali Motavalli

Mohammad Rajabi

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

10.22075/ancr.2014.172

Abstract

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 30h formed a nanocrystalline composite with the average crystallite size of MgH₂ of 17nm and average particle size of 1.4µm. 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 30h MA, revealing catalytic effect of Ni₃FeMn alloy.

Keywords

Magnesium hydride

Mechanical alloying

Hydrogen desorption temperature

Ni3FeMn alloy