Solid solutions of hydrogen in binary alloys based on niobium and tungsten

High purity binary alloys based on niobium and tungsten (W nominal compositions of 2; 7; 10; 15 and 20 atomic %) were doped with hydrogen in equilibrium with the surrounding gaseous atmosphere in different temperature at a partial pressure of 80 Torr. Numerical parameters were calculated for the descriptive curves of hydrogen equilibrium solubility at the partial pressure of 80 Torr. By means of two equivalent equations, deducing the partial molar values of enthalpy and entropy of such interstitial solid solutions. One concludes that adding W to Nb up to the limit of 20 atomic percent, has the effect of lowering the hydrogen equilibrium solubility. (author)