Preparation of ultra fine-grained metal hydride alloy of Mg-Fe system by mechanical milling for hydrogen storage application

The synthesis and characterization of ultra fine-grained metal hydride alloy of the Mg–Fe system by mechanical milling technique have been performed. The Mg and Fe powders were mixed and milled with the variation of milling time 0, 10, 20, 30, 40, 50, 60 and 70 hours. The refinement of the X-ray diffractions reveals that the sample consists of three phases, namely nanocrystalline Mg, Fe, and FeH with the average grain size of approximately less than 5 nm. The observations of the microstructure using SEM shows that the sample consists of very small particles with sizes of about 100 – 500 nm. It is concluded that the ultra fine-grained metal hydride alloy of the Mg-Fe system for hydrogen storage application can be prepared by mechanical milling technique.