Si3N4–Al2O3–TiC–Y2O3 composites intended for the edges of cutting tools

This paper is concerned with the synthesis of composites in the Si3N4–Al2O3–TiC–Y2O3 system. The materials obtained have a high density and a good fracture toughness (KIC=9.3 MPa√m). Machining tests show that the service life of the tool blades made of these composites may even be tenfold longer than that of commercial blades made of Si3N4 with an additon of Al2O3, MgO and Y2O3.