Mg-based Laves phase alloys (Mg0.7M0.3)Ni 2, where M elements were Ca, La, Ce, Pr, Nd and Gd were successfully developed. The alloys can be synthesized by a conventional induction melting and annealing method from intermetallic compounds MgNi2 and MNi 2 as a source of Mg, Ni and M elements. The crystal structures of the major phases of annealed (Mg0.7M0.3)Ni2 alloys were C15-type for M = Ca and C15b-type for M = La, Ce, Pr, Nd and Gd Laves structures, respectively. In the alloys except M = Ce, hydrogenation and dehydrogenation reversibly occurred. The maximum hydrogen contents of the alloys are 1.2-1.6 mass% (H/M:0.6-0.8) under hydrogen pressure of 5 MPa at 243-273 K. As the results of measurements of p-c isotherms, in the case of the M = Pr and Nd, two step plateaus were clearly observed. After a few hydrogenation/ dehydrogenation cycles, the alloys kept C15-type or C15 b-type Laves structures without hydrogen-induced amorphization. disproportionation and decomposition.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering