Zr-Te合金の酸化機構について

Abstract

The beneficial effect of tellurium as an additive on the oxidation resistance of zirconium has been reported. It was stated that the addition of tellurium would decrease the concentration and the mobility of oxygen ion vacancies. Experiments by oxidation test were carried out to determine whether the vacancy concentration or the mobility is mainly affected by the presence of tellurium in the oxide. The results obtained were: tellurium addition was not so effectual at high temperatures as at low temperatures, but the amount of tellurium addition which resulted in the longest breakaway time (i.e., the lowest oxidation amount) was scarcely changed by the oxidation temperature and nitrogen content which was said to increase the concentration of oxygen ion vacancy. From these results it was concluded that a tellurium ion in zirconium oxide does not contribute to the decrease in the vacancy concentration, but mainly to the decrease in the mobility of vacancy by taking the state of positive quadrivalency. (auth)