SOLUBILITY OF HYDROGEN IN MOLYBDENUM AND ITS ALLOYS.

Abstract

Solubility of hydrogen in molybdenum and its binary solid solution alloys containing titanium, zirconium, vanadium and niobium, respectively was measured in the temperature range between 600 abd 1200 degree C under one atmosphere pressure of hydrogen gas. Relative partial molar entropy and enthalpy for hydrogen solubility in molybdenum were obtained as 15. 8 cal/g-atom. deg and 9. 51 kcal/g-atom respectively. The solubility increased with increase in the amount of each alloying element. The entropy of the alloys first decreased with increase in the alloying elements and became almost constant with a value of approximately minus 17. 5 cal/g-atom. deg. In Mo-Ti alloys, and Mo-V and Mo-Nb alloys containing more than about 10 at% of each alloying element, the enthalpy decreased monotonically with increase in electron/atom ratio.