空气中无压烧结Al2O3/SiC陶瓷的微观结构及性能

Study on Micro-structure and Properties of Al_2O_3/SiC Ceramics by Pressureless Sintering in Air

研究了Al2O3/SiC陶瓷在空气中的烧结行为,实现了该体系在空气中的致密化烧结,1600℃添加10%(体积分数,下同)SiC的试样致密度达到97.6%,维氏硬度达到14.45GPa。探讨了烧结温度与SiC含量对Al2O3/SiC陶瓷微观结构和致密度、硬度等性能的影响,高温下烧结可得到较致密的陶瓷,但SiC含量超过30%的试样会产生"夹心"现象。探索了粉末埋烧对陶瓷致密度的影响,表明埋烧的方法可以降低低SiC含量试样的气孔率,起到抑制氧化的作用。

The sintering behaviour in air of the Al2O3/SiC ceramics was studied, and the ceramics had achieved sintering densification successfully, the relative density of the sample adding 10% SiC （volume fraction,the same below）was 97.6%, which had a Vickers hardness of 14.45GPa. The effects of sintering temperature and SiC content on micro-structure, relative density, hardness and other properties were discussed; it could produce relatively dense ceramics at high temperature, but the specimens with more than 30% SiC would form a ＂sandwich＂ structure. The influence of the powder bed on the relative density was investigated, it showed that the powder bed could lower porosity of lower SiC content samples, and control oxidation effectively.