Microstructure and De-/hydrogenation behavior of melt-spun Mg-Ni-Y alloys as hydrogen storage materials

In this contribution, nanocrystalline magnesium-rich Mg-Ni-Y alloys were produced by melt-spinning and were studied in view of their crystal structure, crystallization behaviour and their cyclic hydrogenation/dehydrogenation properties that render them attractive materials for the reversible storage of hydrogen. The alloy composition was chosen for several reasons: From the literature it is known that the addition of Ni to Mg significantly improves the hydriding/dehydriding kinetics and decreases the working temperature compared to that of pure Mg. Further, Y is widely known as glass-forming element in Mg alloys. Moreover, ultrafine yttrium hydride particles improve the hydrogen sorption kinetics of Mg. Finally, ultra-fine crystal phases like yttrium hydrides might stabilize the nanostructure of the alloys by preventing further crystal coarsening during thermal processing.