Effect of Gas Media on Interaction between Products of Intermetallide Destructive Hydrogenation

Abstract

The thermodynamic possibility for interaction between the products of LaNi₅, TiFe, Ti₂Ni, TiNi, Ti₂Cu, TiCu, Ti₃Al, TiAl, Mg₂Ni, Mg₂Cu and ZrMn_2,8 destructive hydrogenation and for their interaction with gases (nitrogen, ammonia, methane, water vapor, carbon dioxide and oxide) is investigated. The recombination of the intermetallides from hydride phases and metals is thermodynamically favored over the temperature range suitable for reversible hydrogen accumulation. The minimum tem-perature for the recombination of intermetallides in hydrogen atmosphere is directly proportional to the titanium content of the intermetallide and products of its destructive hydrogenation. The recombination of Ti3Al proceeds in hydrogen at 1.0 MPa and 1073 K from the products of its destructive hydrogenation. The thermo-dynamic possibility for the transformation of interacting products of destructive hydrogenation of titanium-based intermetallides into noninteracting ones by substitution of titanium hydride by its nitride, carbide, or oxide during interaction with nitrogen or ammonia, with methane or carbon, and with CO₂, CO or H₂O is proved. Thermally stable composite TiH₂–TiN–Ti₃Al–TiAl is obtained by annealing of the products of Ti₃Aldestructive hydrogenation (TiH_x–Ti₃Al–TiAl₂–TiAl) in nitrogen at 2.0 MPa and 1073 K.