助烧剂及烧结温度对SiC复合陶瓷物相和显微形貌的影响

本实验采用无压液相烧结工艺,以三种不同配比的Mg O-Ce O2-Y2O3体系为烧结助剂,烧结温度为1800℃、1850℃和1900℃,Ar气氛保护的条件下,保温2h制备了Si C复合陶瓷。主要研究了助烧剂Mg O、Ce O2、Y2O3的不同配比和不同烧结温度对陶瓷体的物相组成、显微组织结构的影响,结果表明:陶瓷体的主晶相均为6H-Si C,有少量的铈和钇的化合物的衍射峰存在;随着烧结温度的升高,陶瓷体孔隙逐渐减小,颗粒与颗粒连接逐渐紧密,在1900℃时可以清晰看出颗粒与颗粒之间存在大量液相,边界趋于模糊,孔隙最少。

In this experiment, the SiC Composite ceramic was prepared with three different proportioning MgO-CeO2-Y2O3 system as sintering additive, sintering temperature was 1800℃, 1850℃ and 1900℃ respectively under Ar atmosphere for 2h. The effects of different ratios of MgO, CeO2 and Y203 and different sintering temperatures on the phase composition and microstructure of ceramics show that the main crystalline phase of the ceramic body is 6H-SiC, and the diffraction peaks of a small amount of cerium and yttrium compounds are exist. The porosity of ceramic body is gradually reduced, the particles are connected with each other gradually with the increase of sintering temperature, and there is a lot of liquid phase between particles in 1900℃, the boundary tends to be blurred and the pores are the least.