Preparation of porous SiC ceramic with a woodlike microstructure by sol-gel and carbothermal reduction processing
Preparation of porous SiC ceramic with a woodlike microstructure by sol-gel and carbothermal reduction processing
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DOI：
10.1016/j.jeurceramsoc.2003.10.042
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发表时间：
2004-09
影响因子：
5.7
通讯作者：
Junmin Qian;Jiping Wang;G. Qiao;Z. Jin
中科院分区：
文献类型：
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作者：
Junmin Qian;Jiping Wang;G. Qiao;Z. Jin
以紫椴木材为原料，采用真空/加压浸渗法将硅溶胶浸渗到多孔生物炭模板中，制备了炭/SiO2复合材料，并在氩气保护下进行碳热还原反应，制备了具有木质结构的多孔碳化硅陶瓷。采用扫描电子显微镜（SEM）、X射线衍射（XRD）、傅立叶变换红外光谱（FTIR）、热重分析（TGA）和差示扫描量热分析（DSC）等技术研究了多孔SiC陶瓷的形貌以及木材向多孔SiC陶瓷转化的机理。实验结果表明，紫椴木炭组织的细胞形态在多孔SiC陶瓷中得到了很好的保持，陶瓷的主要成分为β-SiC和少量的α-SiC。随着SiO2含量的增加，SiC陶瓷的支柱厚度变薄，甚至部分消失。SiC陶瓷的形貌表明，在炭-陶瓷转化过程中发生了固-固、气-固和气-气反应。
Highly porous silicon carbide ceramic with a woodlike microstructure has been prepared by carbothermal reduction reaction of charcoal/silica composites in static argon atmosphere, which were fabricated by infiltrating silica sol into a porous biocarbon template from tilia amurensis wood using a vacuum/pressure infiltration process. The morphology of resulting porous SiC ceramic, as well as the conversion mechanism of wood to porous SiC ceramic, have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Experimental results show that the biomorphic cellular morphology of tilia amurensis wood charcoal tissue is remained in the porous SiC ceramic with high precision which consists of β-SiC with traces of α-SiC. The strut thickness of resulting SiC ceramic becomes thinner, even partially disappears with the increase of silica amount contained in the charcoal/silica composites. The morphology of the SiC ceramic reveals that solid–solid, gas–solid and gas–gas reactions occurred during the charcoal-to-ceramic conversion.