Examination of the kinetics of Zr1.02Ni0.98 alloy hydriding

The hydriding kinetics of Zr1.02Ni0.98 alloy was examined in dependence on the number of hydriding/dehydriding cycles. The rate constants relating to three subsequent hydriding procedures of an alloy sample, at five temperatures: 423, 448, 473, 498 and 523 K, were determined. The rate constant increases, and the activation energy decreases on each repetition of the hydriding/dehydriding cycle at a given temperature. This behavior was explained by sample crushing, leading to an increase in the surface area accessible to hydrogen.