无压烧结制备表面微孔碳化硅陶瓷

Pressureless Sintering of Microporous Silicon Carbide Ceramics

以碳化硅(SiC)微粉为骨料,Al2O3-Y2O3为烧结助剂,氯化钙(CaCl2)作为造孔剂,采用无压液相烧结制备了表面微孔SiC陶瓷,分析了不同CaCl2含量对SiC陶瓷的烧结性能、显微结构和摩擦性能的影响。结果表明:加CaCl2会降低SiC陶瓷的体积密度、硬度和抗弯强度;可以有效地细化SiC陶瓷晶粒;能在SiC陶瓷表面形成许多分布均匀的微小气孔及气孔群,有效地降低SiC陶瓷的摩擦系数。

With SiC powder as raw materials,Al2O3-Y2O3 as sintering additive and calcium chloride as pore former,microporous silicon carbide ceramics were prepared by pressureless sintering.The effects of CaCl2 on the sintering properties,microstructure and friction performances of SiC ceramic specimens were studied.The results showed that calcium chloride decreased the density,hardness and bending strength of SiC sinters and miniaturized the crystal size of SiC ceramics.There were lots of pores on the surface of SiC ceramics.The addition of CaCl2 reduced the friction coefficient efficiently.