Hydrogen storage properties of 2Mg–Fe after the combined processes of hot extrusion and cold rolling

Bulk consolidated samples of 2 Mg–Fe were produced by hot extrusion and by hot extrusion followed by cold rolling. The starting 2 Mg–Fe mixture was obtained by high-energy ball milling. The cold-rolled samples, which presented a favorable (0 0 2) texture in Mg, absorbed 5.23 wt.% H2, almost the full capacity of Mg2FeH6, without any incubation time. This level of hydrogen absorption capacity was higher than the ones observed for the milled powders or the extruded samples. The hydrogen desorption temperatures were very close for all types of samples. The good results observed in the hot-extruded plus cold-rolled sample were explained by the smaller grain sizes, along with a favorable texture and the catalytic effect of residual Fe.

• Nanopowders of 2 Mg–Fe were hot extruded and cold rolled.
• This produced Mg-preferential (0 0 2) texture.
• Increase of both H-capacity and kinetics of the formation of Mg2FeH6 complex hydride was observed in these samples.