Tool ceramics based on Al^sub 2^O3-ZrO2-TiCN composite

Oxide composite Al^sub 2^O3-ZrO2(Y^sub 2^O3) powders containing 50 and 70 vol.% Al^sub 2^O3, are deposited from salt solutions. The surface area of the deposited powders exceeds 75 m^sup 2^/g. It is established that the α-Al^sub 2^O3 and t-ZrO2(Y^sub 2^O3) matrix has an effect on stepwise crystallization of α-Al^sub 2^O3 and the powder production history on the sinterability of oxide composites. Ceramics based on Al^sub 2^O3-ZrO2(Y^sub 2^O3) composite powder containing 20 vol.% titanium carbonitride are hot pressed to be used as a cutting tool. The microstructure and mechanical properties of the ceramics are analyzed. The best mechanical properties are shown by ceramic samples sintered at 1550°C at 35 MPa: bending strength 950 MPa, fracture toughness 10.1 MPa m^sup 1/2^, and hardness 18.0 GPa. The performance and lifetime of cutting tools based on these ceramics are tested according to GOST 26613-85.[PUBLICATION ABSTRACT]