METHOD OF MAKING YTTRIUM SILICON OXYNITRIDES

摘要

A method of making a powder additive consisting of yttrium silicon oxynitrides, preferably of the Y10Si6O24N2 or YSiO2N phases, is disclosed. Stoichiometric amounts of Y2O3, SiO2, and Si3N4 are mixed and arranged in intimate reactive contact, the amounts being to form a desired oxynitride according to the formula YaSibOcNd, where a, b, c and d represent the required element parts of the compound in equilibrium with the mixture elements. The mixture is heated in an inert atmosphere to a temperature and for a time sufficient to convert the stoichiometric amounts of the mixture to the desired yttrium silicon oxynitride. The heat agglomerated mixture is then ground to a powder.