Sinterable ceramic compositions

Abstract

Hard crystalline sintered ceramic products, and a method for making them at substantially reduced sintering temperatures, are disclosed, the products being manufactured by the sintering of mixtures comprising one or more ceramic powders selected from among zirconia, stabilized zirconia, partially stabilized zirconia, alumina, mullite, cordierite, and MgAl.sub.2 O.sub.4 spinal together with a combination sintering aide including TiO.sub.2 and at least one transition metal oxide selected from the group consisting of copper oxide, manganese oxide, cobalt oxide and zinc oxide, the mixture comprising at least about 3.5 mole percent TiO.sub.2, at least about 1.3 percent of transition metal oxides, about 4.8-50 mole percent total of TiO.sub.2 +transition metal oxides, and the remainder ceramic powder. Sintering of these mixtures at temperatures typically 200.degree.-350.degree. C. below the pure powder sintering temperatures of the base ceramics provides products with open porosities less than 5% by volume, more typically 0-2% by volume.

Dependencies are inferred from the claim text.