Study on the Performance for Silicon Carbide Ceramics by Hot-pressing Sintering

SiC ceramics were prepared by hot-pressing sintering technique and α-SiC、β-SiC powders were utilized as raw material, B4C as sintering additives. Orthogonal test designed to analyse the microstructure and sintering characteristics for SiC ceramic with the sintering temperature, holding time and sintering pressure as the influencing factors, Results showed that 99.2% relative density of SiC ceramics can be obtained under the condition of 1900 ℃ sintering temperature, 60 min holding time and 50 Mpa sintering pressure. A mass of long columnar grains were generated as the addition β-SiC at 10%, and the fracture toughness and bending strength also increased at the same time, while weak interface combination not concluded for solid phase sintering, so the enhancement for the overall performance of the SiC ceramics is restricted.