Microstructures and hydrogen storage properties of La-Ni-Fe-V-Mn alloys

Multicomponent high entropy alloys based on LaNis phase are investigated as hydrogen storage materials. The multicomponent La-Ni-Fe-V Mn alloys are produced from prealloyed and elemental gas-atomized powders using Laser Engineered Net Shaping (LENS) technology. The effect of the alloy chemical composition on the hydrogen storage properties are elucidated in terms of the structure, phase composition and alloy formation entropies. The results of phase analysis indicates that laser manufactured alloys possess primary two-phase structure that changes from sigma + La(Ni,Mn)(s) to FCC + La(Ni,Mn)(s) alloys. Maximum hydrogen capacity of La-Ni-Fe-V Mn alloys is proportional to the atomic content of lanthanum which is able to form CaCus-type La(Ni,Mn)(s) phase. Produced alloys show differential behavior while forming the hydride phase and no simple relationship between phase compositions and pressure-composition curves can be observed. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.