Patent ID: 6905992

Claim:
A ceramic cutting tool comprising: a ceramic composite having a rake face and a flank face, the rake face and the flank face intersect to form a cutting edge; the ceramic composite is made by compacting a starting powder blend comprising: between about 50 volume percent and about 99 volume percent of a ceramic matrix; and between about 1 volume percent and about 50 volume percent as-processed silicon carbide whiskers wherein the as-processed silicon carbide whiskers comprise silicon carbide whiskers subjected to a heat treatment and a mechanical treatment; and the ceramic composite having a fracture toughness (K IC ) of greater than about 4.0 MPam 1/2 , and the ceramic composite having a silicon carbide whisker density as measured in whiskers per square millimeter equal to or less than about 1500 times the volume percent of silicon carbide whiskers, but in a density sufficient for the ceramic composite to have said fracture toughness.