氮气中C-Si系材料的高温变化过程  

High-temperature reaction process of C-Si system materials in nitrogen atmosphere

作　　者：邓承继[1] 祝洪喜[1] 易成雄[1] 白晨[1] 石生德[2] 

机构地区：[1]武汉科技大学耐火材料与高温陶瓷国家重点实验室培育基地,湖北武汉430081 [2]武汉钢铁(集团)公司硅钢厂,湖北武汉430082

出　　处：《武汉科技大学学报》2008年第3期268-272,共5页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金资助项目(50772079);湖北省自然科学基金资助项目(2007ABA050)

摘　　要：以9组不同配料比的炭黑和单质硅为原料压制成试样,在氮气气氛下,分别于1 350,1 400,1 450,1 500,1 550℃下烧结,获得5个不同温度点合成样品;采用XRD分析技术研究试样的物相演变过程,研究C-Si系原料在氮气气氛合成过程中的物相变化和反应动力学机制。试验结果表明:试样在氮气气氛下合成,最终物相为SiC,α-Si3N4和β-Si3N4,硅含量高时还存在Si2N2O相,石英相和方石英相作为中间产物出现;氮化硅不仅可由单质硅氮化生成,还可由SiO2,Si2N2O与C还原氮化生成,α-Si3N4先于β-Si3N4生成,且温度升高会向β相转化,温度高于1 500℃时,Si3N4会与残余的C反应生成SiC;合成温度和配料比是影响C-Si系原料合成产物的重要动力学因素。Nine groups of samples, prepared from carbon black and industrial Si at different ratios, were fired in nitrogen atmosphere at five temperatures of 1 350℃, 1 400℃, 1 450℃, 1 500℃ and 1 550℃, respectively. By using XRD technique, the phase compositions of the sintered samples were analyzed, and the influence of formula and synthesized temperature on the synthesis was investigated, with the related dynamic mechanism explained. It is found that, in nitrogen atmosphere, the final phases of the samples are SiC,α-Si3N4 and β- Si3 N4, and Si2N2O may also appear when the percentage of Si is large; quartz and cristobalite appear as intermediate products; silicon nitride can be produced not only by the reaction between Si and N2 but also from the reduction nitridation of SiO2, C and N2, or Si2N2O, C and N2. In addition, α-Si3N4 always appears earlier than β-Si3N4, and changes into β- Si3N4 with the increase of the temperature. When the synthesized temperature is above 1500℃, SiC phase is produced by the reaction between Si3N4 and the rest C in the samples. The sintered temperature and the starting materials compositions are key factors in influencing the synthetic products of the sintered samples.

关 键 词：C-Si系原料 氮气气氛 合成 

分 类 号：TB321[一般工业技术—材料科学与工程]