成型温度对多孔SiC陶瓷性能的影响

以包混工艺合成了核-壳结构的先驱体粉体,并引入少量Al<,2>O<,3>,SiO<,2>和Y<,2>O<,3>作为复合添加剂,通过模压成型、炭化和烧结工艺制备了多孔碳化硅陶瓷;研究了成型温度对样品的孔隙率、密度、热膨胀系数、抗弯强度和热震性能的影响.结果表明:成型温度对多孔碳化硅陶瓷的孔隙率、密度、抗弯强度及热震性能均...

Effects of Molding Temperature on Properties of Porous SiC Ceramics

The core-shell structure precursor powders were synthesized through coat mix process,and a small amount of Al2O3,SiO2 and Y2O3 composite additives was added.A series of porous silicon carbide ceramics were produced after molding,carbonization and sintering.The porosity,density,thermal expansion coefficient,bending strength and thermal shock resistance of porous silicon carbide ceramics were analyzed.The results show that the porous silicon carbide ceramic with molding temperature 80℃ possesses best general performance.When the molding temperature is very low,the barium phenolic resin coated over the core-shell structure precursor powders can not flow adequately,leading a loose structure and lower strength for the final porous silicon carbide ceramic.While the phenolic resin flows too much with excessive high molding temperature,some of composite additives are coated by phenolic resin and can not touch each other adequately,thereby the effect of composite additive is weaken.