| The influence of different TiC and TiN amounts on the sintering, the properties and the microstructrue was obtained in this paper. The samples with different amount of TiC and TiN were obtained by using pressureless sintering at 1600 ℃ , 1700 ℃ , 1800 ℃ in the nitrogen atmosphere. The microstructure and composition of the cermits were detected by the SEM, micro-hardness meter etc.It was showed that the relative density, Vickers hardness, Fracture toughness were low by using pressureless sintering in the nitrogen atmosphere at 1600 ℃ ,Because Al2O3 matrix has been sintered and thin, a composities with 17.6GPa Vickers hardness and 4.27Mpa.m1/2 Fracture toughness was obtained.At the same time, TiC and TiN matrix began to sinter,But Vickers hardness and Fracture toughness was down at the different degree for the Al2O3 matrix rising. It was showed that 1700 ℃ was a good sintering temperature.The properties will vary with different amount of TiC and TiN. Vickers Hardness is rising with the increasing amount of TiC and the max is 17.6GPa. Fracture toughness is rising with increasing amount of TiN and the max is 4.27Mpa. Because TiC possesses excellent Vicker Hardness and the fracture toughness of TiN is wonderful.Different kind sintering may lead the same sample shows different property. The Al2O3-TiC-TiN Cermits are sintered respectively under pressureless, 10MPa and 20MPa, at 1600℃ for 3 hours. The results show the density and mechanical properties have been greatly improved.The max Vickers Handness is 19,4 GPa, themax Fracture tonghtness is 5.20 MPa□m1/2...
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