LIQUID PHASE SINTERED α-silicon CARBIDE WITH AlN-Re2O3 AS SINTERING ADDITIVE

摘要

The (falsification of α-SiC occurred by liquid-phase sintering mechanism with AlN-R2O3(La2O3,Nd2O3,Y2O3)was studied. The total additive content was fixed at 17.5 wt %. Cold isostatically pressed samples were sintered at 1800-1950 °C under N2 atmosphere for 1hr. The linear shrinkage and weight loss of the samples were about 17-20% and 2-5% respectively. The mechanical properties and microstructure of sintered samples were investigated. The experimental results showed that the fracture toughness of samples was 6-8MPa.m~(1/2), the hardness was in the range of 18-21GPa and the bending strength was in the range of 400-500 MPa. The SEM of sintered sample showed a fine grained microstructure with equiaxed grains. Fracture mode was intergranular fracture.