以Si-C-N纳米微粉为增强相,Si₃N₄为基相,采用热压的方法制备了SiCp/Si₃N₄纳米复相陶瓷.应用扫描电镜(SEM)、高分辨透射电镜(HRTEM)对其结构进行了观察,并讨论了结构与性能之间的关系.结果表明,所得的SiCp/Si₃N₄复相陶瓷的室温力学性能比氮化硅单相陶瓷有较大的提高,而1350℃断裂韧性达14.66MPa·m^1/2.SiC微晶在晶粒内和在晶界玻璃相内的钉扎作用是材料高温性能提高的主要因素.

Nano sized Si-C-N powders mixed with Si₃N₄,Y₂O₃,La₂O₃ was hot press sintered to form the SiC/Si₃N₄ composites.The microstructure of the composite was observed by means of SEM and HRTEM.The results show that the toughness and three point bending strength of the composite at room temperature is higher than those of monolithic Si₃N₄.The fracture toughness at room temperature and 1350℃ is 11.78 MPa·m 1/2 and 14.69 MPa·m^1/2 respectively.The bending strength at room temperature and 1350℃ is 934MPa and 696MPa respectively the pinning effect of the SiC micro-crystal in Si₃N₄ grain and in grain boundary glass phase prevents the strength loss and increases the toughness of the composites at elevated temperature.