碳模板转化法制备管状SiC/Si复合陶瓷

Fabrication of tubular SiC/Si ceramic composites by carbon template conversion

利用纸作为原材料,通过卷曲、树脂浸渍、碳化预制备出具有层状结构的管状碳模板,之后在1550℃通过原位反应液相渗Si0.5-1h,在常压烧结条件下制备出具有层状结构特征的SiC/Si管状陶瓷复合材料.采用XRD、SEM对碳模板反应前后的物相变化和显微结构进行了研究.结果表明了该材料的最终产物为β-SiC和Si,且两者分布表现出明显的交替成层现象,呈现出层状陶瓷的结构特征.

SiC/Si tubular ceramic composites were synthesized successfully using paper as raw material. By rolling the paper to tubular shape,marinating it with phenolic resin and carbonizing it at 800 ℃ for 2 h,we fabricated tubular carbon templates. And then laminated SiC/Si ceramic composites were prepared by in-situ reaction with molten silicon at the temperature up to 1550 ℃ in Ar atmosphere for 1-2 h. XRD analysis shows that the final product is composed of beta-SiC and free silicon. SEM exhibits a distinguished multilayered structure consisting of alternate SiC and Si layers. The load-displacement curve of laminated Si/SiC ceramic composites shows a non-catastrophic fracture behavior,which is attributed to the multilayered morphology and the toughening of bar-shaped SiC grains.