Thermodynamic Analysis of the Formation and Decomposition of Intermetallic Hydrides


I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2010, #11/12


The formation and decomposition of intermetallic hydrides LaNi5H6, TiFeH2, Ti2NiH, TiNiH2, Ti2CuH2,7, TiCuH, Ti3AlH3, Mg2NiH4, Mg2CuH3, and ZrMn2,8H4 are thermodynamically analyzed in identical conditions. These reactions are competitive and the interface between them is determined by the boundary composition AxByHnbound. For intermetallic compounds LaNi5, TiFe, Mg2Ni, and ZrMn2,8, the range of stable hydrogenation is accordingly equal to 17, 27, 5, and 17% of the maximum hydrogen capacity, and the rest are the range of metastable hydrides in which the decomposition reactions are limited kinetically. The improvement in kinetics of intermetallide hydrogenation prevents the decomposition of the intermetallides hydrides. It is achieved by the mechanical or catalytic activation of hydrogenation and by the use of heat-conducting non-volatile metal-matrix composites based on intermetallides.