【摘要】 通过对SiC/C层状复合材料烧结工艺的系统研究,得出该材料在烧结助剂质量分数为2%Al2O3、6%Y2O3,烧结温度1900℃,保温1h,加压30MPa的烧结工艺较为合理。复合材料较块体SiC断裂韧度提高了74.5%,其断裂方式呈现出“假塑性”,层状复合陶瓷的增韧机制主要是由于弱夹层的存在引起裂纹偏转、分支、止住而吸收能量。更多还原

【Abstract】 A SiC/C laminated composite was fabricated by tape casting and hot-pressing sintering, its fracture toughness increased 74. 46% compared with the block of SiC. It was gained by a reasonable sintering process with additions of 2% Al2O3 and 6% Y2O3 as sintering-aid-agents, holding at 1 900 ℃ for 1h at a pressure of 30 MPa. The fracture of the laminated ceramic composite, which was different from that of monolithic ceramics, exhibited "pseudoplasticity". The main toughening mechanism of laminated ceramic composites might be attributed to the present of graphite layers, which caused deflection, bifurcation, obsorbing energy and stop of cracks.更多还原