摘要 |
A cutting tool tip is formed at least at a cutting edge of the tip from a ceramic product consisting essentially of at least 75% by volume of a single phase compound having an expanded beta -phase silicon nitride lattice and having the general formula Si6-zAlzN8-z Oz, where O<z</=5, together with a second phase containing a metal from the list yttrium, lanthanum, cerium and scandium, or other rare earth metal. |