Ti-Cr-V 系合金の水素化サイクル特性に及ぼす微細構造の影響

The cyclic degradation of TiCrV hydrogen storage alloy has been studied by using SEM and TEM. Microstructural analysis indicated that the accumulation of lattice defects such as dislocations and strain field occurred due to volume expansion and shrinkage during cycles, led to a loss of the effective storage capacity. Annealing with minute particles in order to suppress the development of lattice defects during cycles resulted in increase in plateau width during hydrogenation but nothing improved during de-hydrogenation. This is probably due to beta-hydrides formed during hydrogenation, which is stable with lattice defects and strain field. Fine particles less than several hundred nano-meter in size could have a good degradation resistance due to less accumulation of lattice defects and during cycles.