Study On Preparation Of SiC Ceramics Derived From Bamboo Charcoal

In this paper bamboo charcoal was used as raw materials to produce SiC ceramics by Si-infiltration and Sol-gel at high tempreture. The structure and property were investigated by means of DSC, FT-IR, SEM-EDS, XRD and so on. Based on the experiment, the research content and conclusion are described as followed:(1)we studied the physical and chemical properties of bamboo charcoal. And it had high fixed carbon content(88.91%), which basically suited to the needs of this experiment.(2)The experiment used bamboo charcoal powder,silica powder as raw materials, then mixed phenolic resins or SiO2 sol in terms of definite proportion, and solidified them to stated shape. The samples were heated from 1500 to 1800℃for 0.5 hr in argon atmosphere resulting in the formation of SiC ceramic.(3)The SiC ceramics prepared by two methods had many of the same characteristics in many ways. The results showed that there were obvious heat changes during high-temperature processing, and chemical bond was transformed from Si-O to Si-C. The microstructures of bamboo charcoal remained in the SiC ceramic and a high concentration of Si element lined the surfaces of SiC ceramic materials. In addition, there were some SiC crystal whiskers in it. XRD analysis indicated that the ceramics obtained above 1650℃mainly consisted of SiC with trace amounts of elemental carbon and silicon.(4)The SiC ceramics prepared by two methods had lower density, which were 0.73g/cm3 and 1.14g/cm3. The SiC ceramic obtained at 1650℃by Si-infiltration had higher Benzene adsorption rate and TVOC adsorption rate, which were 5.25% and 2.38%, and the SiC ceramic obtained at 1650℃by Sol-gel had higher Benzene adsorption rate and Ammonia adsorption rate, which were 6.14% and 3.55%. The ceramics had lower resistivity(15.22?﹒cm), which were good semiconductor materials, and the resistance-corrosion rate was more than 99%. In addition, the materials had better resistance toward oxidation and high tenpreture.(5)Pore theory was used to analyzed the trace of liquid Si and SiO2 sol infiltration, and reaction mechanism of Si and C were also discussed.