On the zirconium-oxygen-hydrogen ternary system

Thermodynamic studies on the Zr-O-H ternary system have been carried out, based on the hydrogen solubility for alpha Zr(O), beta Zr(O) and ZrO2. The dissolved oxygen in zirconium strongly affected both the hydrogen solubility and the phase diagram. The effect of the interstitial oxygen on the hydrogen solubility was discussed on the basis of the partial molar quantities of hydrogen in the Zr-O-H ternary solid solutions. The hydrogen dissolution into the ZrO2 was studied in O-2/H2O atmosphere using a thermal desorption method. The hydrogen solubility in the ZrO2 was evaluated from the thermal desorption spectra to range from 10(-5) to 10(-4) mol H/mol oxide and decreased with increasing temperature. (C) 1999 Elsevier Science B.V. All rights reserved.