Patent ID: 7262145

Claim:
A ceramic body comprising: a matrix comprising aluminum oxynitride and a ceramic additive other than aluminum oxynitride; whiskers distributed throughout the matrix; the aluminum oxynitride comprising between about 30 volume percent and about 45 volume percent of the ceramic body; the ceramic additive comprising between about 10 volume percent and about 40 volume percent of the ceramic body; the whiskers comprising between about 2 volume percent and about 40 volume percent of the ceramic body; and wherein a source of the aluminum oxynitride is aluminum oxynitride powder that contains less than or equal to about 0.1 weight percent aluminum nitride; and wherein the whiskers comprise silicon carbide whiskers and the ceramic additive comprises one or more of the following materials taken separately or in solid solution with each other or other elements: titanium carbonitride, hafnium carbonitride, and boron carbide, the Vicker's Hardness Number (VHN) determined per ASTM E384-99e1 being at least about 17.00, and the fracture toughness (K IC ) per Evans and Charles being at least about 5.0 MPa·m 1/2 .