Structural characterization and hydrogen sorption properties of nanocrystalline Mg2Ni

The effect of high-pressure torsion on the microstructure and hydrogen absorption kinetics of ball-milled Mg70Ni30

“…A usual tendency is confirmed, i.e. both Mg and Ni achieve nanometric dimensions with final grain sizes of D = 13 nm and D = 30 nm, respectively, in correlation with literature data [34]. The faster microstructural refinement of Mg compared to Ni results in Mg-enriched grain boundaries compared to the grain interiors coupled with increased reactivity to produce the amorphous phase [33,35].…”

“…The subsequent T 2 transformation promotes the nucleation of the Mg 2 Ni compound phase at the expense of Mg and Ni, in accordance with the equilibrium phase diagram. The T 2 temperature characterizing the Mg + Ni → Mg 2 Ni is considerably higher than for BM-Mg 2 Ni [34] due to the increased thermal stability induced by the severe shear deformation.…”

Hydrogen storage of nanocrystalline Mg–Ni alloy processed by equal-channel angular pressing and cold rolling

“…3a. The value obtained for the Mg 2 Ni compound phase characterizing the as-milled powder (D=15 nm) and the as-pressed billet (D=18) nm is in line with literature data [16,33]. With increasing ECAP deformation, only a moderate crystallite size reduction is noticed (D=13 nm for ECAP 6x).…”

Effect of ZrCrCo alloy on hydrogen storage properties of Mg

“…They have shown that nano-crystalline magnesium with 1.5 at% Zr is capable to desorb hydrogen at lower temperature ($280°C) within few minutes. Another approach of alloying Mg with the transition metal to form Mg 2 Ni [13], Mg 2 Co [14], Mg-La [15] succeeded to destabilize MgH 2 and the enthalpy is reduced from À76 kJ mol À1 for MgH 2 to À64 kJ mol À1 for Mg 2 NiH 4 [13]. However, the addition of heavier transition metal lowered the hydrogen capacity too.…”