摘要
本工作研究了SiO_2与C反应法合成SiC晶须的条件及机理;藉此法在Si_3N_4基体粉末内合成了均匀分布的SiC晶须,并制备出SiC晶须补强的Si_3N_4复合材料(因不用任何外加晶须,这类材料可称为“自补强陶瓷复合材料”)。该材料(SiC晶须的体积含量为15%)具有优良的机械性能:K_(Ic)=8.0MPa·m^(1/2),σ(b,RT)=649MPa;1300℃空气中氧化100h后,σ(b,1300℃)=621MPa。其显微组织特征是:SiC晶须均匀分布于Si_3N_4晶粒之间;也有纳米级的SiC颗粒镶嵌在Si_3N_4晶粒内,少量位于其晶界上。
The growth conditions and mechanism of SiC whiskers synthesized by carbothermal reduction of silica are described in present paper. This method was used for preparing SiC whiskers which distributed homogeneously in the matrix of Si_3N_4 powder, and then Si_3N_4 composites with SiC whisker reinforcement were prepared, Since no additional whiskers are needed, this kind of materials may be referred to as 'self-reinforced ceramic-based composites'. These composites have good mechanical properties at 15%(vol) SiC_w:K_(IC)=8.0MPa.m^(1/2); σ(b,RT)=649MPa;σ(b, 1300℃)=621MPa (after oxidation at 1300℃ for 100h in air). The microstructural characteristies of SiC_w/Si_3N_4 composites are: SiC whiskers are homogeneously distributed among Si_3N_4 grains with nanometer-sized SiC particles trapped in the grains, only a few located on the grain boundaries
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1993年第1期1-9,共9页
Journal of The Chinese Ceramic Society
基金
863计划资助项目
关键词
碳化硅
晶须
氮化硅
陶瓷
self-reinforced
silicon carbide whisker
silicon nitride
composite