The variation in crystal structure with substitution of the Zr site of ZrM2 (M2 V0.5Ni1.1Mn0.2Fe0.2) by Ti, Nb or Hf has been studied. The C14 and C15 Laves phases coexist for all alloys except TiM2 (b.c.c.), Zr0.25Ti0.75M2 (87% C14 and 13% b.c.c.), Zr0.5Ti0.5M2 and NbM2 (pure C14). The C15 phase cannot accommodate an M siteM site bond distance of less than 2.46 Å. The phase stability under hydriding is confirmed. The pressure-composition isotherm measurements show that the multiphase alloys behave as a single phase. Also, the b.c.c. phase alloy TiM2 can absorb hydrogen. For electrode performances, it is observed that the alloys with the C15 phase present a large reduction in discharge capacity when the discharge current is increased. For the alloys composed of only the C14 phase, the discharge capacity does not change significantly when the discharge current is increased.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry