PROCESS FOR MAKING A HOMOGENEOUS DOPED SILICON NITRIDE ARTICLE

摘要

PROCESS FOR MAKING A HOMOGENEOUS DOPED SILICON NITRIDE ARTICLE A process for making a homogeneous yttria-alumina doped silicon nitride article is described. A uniform coating of yttria and alumina is applied to the surface of silicon nitride particles by a chemical application of the hydroxides of yttrium and aluminum followed by drying and a subsequent convertion of the hydroxides to the corresponding oxides. The resulting powder is formed into an article and pressureless sintered to a density greater than 99% of theoretical.