Patent ID: 6740611
Filing Date: 2004-05-25
Classification: C04B,Y10T

Abstract:
An alumina-based composite sintered material comprising alumina grains as a main ingredient and containing at least one carbonitridation product of at least one element of groups IVa, Va and VIa of the periodic table and/or at least one carbonitridation product comprising a solid solution of two or more elements of groups IVa, Va and VIa of the periodic table, said carbonitridation product comprising grains interposed between said alumina grains having a nucleus made of a carbide of at least one element of groups IVa, Va and VIa of the periodic table, said sintered material having an interior including a center and a surface,wherein the carbonitridation product has a content of nitrogen solid solute that increases from the interior to the surface of the sintered material, and the Vickers hardness at the surface of the sintered material is 19.5 GPa or more.