Hydrogen permeation of Ni-Nb-Zr metallic glasses in a supercooled liquid state

In this study, the hydrogen permeation in the supercooled liquid state for Ni₆₅Nb₂₅Zr₁₀, Ni₆₀Nb ₂₀Zr₂₀ and Ni₅₅Nb₁₅Zr₃₀ metallic glasses was investigated in conjunction with the discussion on the effect of hydrogen diffusion on hydrogen permeation. The hydrogen permeation of the Ni₆₅Nb₂₅Zr₁₀ and Ni₆₀Nb ₂₀Zr₂₀ metallic glasses increases significantly by the transition from the glassy solid state to the supercooled liquid state. The temperature at which this significant increase in hydrogen permeation appears is much lower than T_g and is in correspondence with the onset temperature of the endothermic reaction relating to the glass transition. Moreover, it was found that the hydrogen permeation in the glassy phase was larger than that in the corresponding crystalline one. The contribution of hydrogen diffusion and solution to permeation is discussed in detail.