摘要
本文以0.8μm改性SiC粉采用凝胶注模成型制备了超细晶反应烧结碳化硅陶瓷。研究了压制和凝胶注模两种成型方式对反应烧结碳化硅的微观结构及材料性能的影响。SEM分析显示,PF成型的素坯中微孔结构分布不均,GC成型的素坯中SiC与C相互包裹均匀分散,坯体的孔结构均匀;RBSC材料金相观察表明,采用常规的压汞仪测试不能真实反映素坯的孔结构。GC成型的RBSC中SiC和游离硅(fSi)的分布均匀细小是材料强度提高的主要原因。
In this paper,the effects of pressure forming and gel-casting on the microstructure and bending strength of RBSC have been presented.SEM analysis indicated that the green-compact acquired by pressure forming revealed an uneven distribution of micro-pore structure,while the green body formed by gel-casting showed a uniform microstructure： SiC and C surrounded by each other and dispersed homogeneously.Microstructure analysis showed that the combination of metallographic observation and mercury penetration analysis could reflect the structure of the green body more accurately.Compared with pressure forming,RBSC obtained by gel-casting showed a more uniform distribution of free silicon,which was an important factor for the improvement of RBSC＇s bending strength.The RBSC with a uniform microstructure and fewer internal defects was obtained by Gel-casting using the modified SiC powder（0.8μm） and the highest bending strength came up to 690MPa.
出处
《陶瓷学报》
CAS
北大核心
2011年第3期407-411,共5页
Journal of Ceramics
