造粒粉体对SiC陶瓷力学性能及微观组织的影响

Effect of Granulated Powders on Mechanical Properties and Microstructure of SiC Ceramics

采用无压烧结法制备Si C陶瓷,研究了4种不同Si C造粒粉对陶瓷烧结体力学性能的影响,采用激光粒度仪检测了不同造粒粉体的粒度,利用SEM观察了不同造粒粉体及烧结体的微观形貌。试验结果表明:不同造粒粉对Si C陶瓷力学性能的影响差异较大,其中,由Si C-1造粒粉制得的陶瓷烧结体力学性能最佳,弯曲强度为318 MPa,洛氏硬度为94.0 HRA,密度为3.1367 g/cm3。结合微观组织分析可知,Si C-1造粒粉粒径较小,制得的陶瓷烧结体气孔较小且裂纹较少,基本无游离Si和游离C存在,综合性能较好。

Pressureless sintering has been used to prepare SiC ceramics, and the effect of four kinds of granulated powders on the mechanical properties of sintered SiC body has been studied. Laser particle sizer has been used to detect the particle size, the microstructure of different powders and the sintered body has been observed by SEM. The results show that different granulated powders of SiC obviously affect the mechanical properties of the sintered SiC body. The sintered body obtained from granulated SiC-1 powders is the optimum with the lfexural strength of 318 MPa, the hardness of 94.0 HRA and the density of 3.1367 g/cm^3. Combined with the microstructure analysis, the sintered body prepared from granulated SiC-1 powders has better properties because of smaller pores and fewer cracks and no free Si and C, as well as the ifner size of the granulated powders.