Alumina-Zirconia Fine Powders Prepared by Hydrothermal Oxidation

Abstract

Fine powders of alumina-zirconia mixtures were prepared by hydrothermal oxidation of Al-Zr alloys which were fused in an arc image furnace. The hydrothermal oxidation of Al-Zr alloys proceeded above 500°C under 100MPa for 3h, and the obtained powders consisted of monoclinic zirconia, tetragonal zirconia and alpha-alumina. The average crystallite sizes of these phases were 13-24nm, 9-12nm, 27-35nm, respectively, smaller than that of monoclinic zirconia or alpha-alumina (which was) prepared by hydrothermal oxidation of Zr or Al metal under the same condition. Alumina-zirconia powders prepared by this method were homogeneous mixtures of alumina and zirconia particles of which sizes were around 30nm as determined by Transmission electron micrograph (TEM) observation.