熔盐镁热还原制备SiC纳米粉体及其氧化动力学  

Preparation and Oxidation Resistance of SiC Nano-powder by Molten-Salt-Mediated Magnesiothermic Reduction Method

作　　者：葛胜涛 谭操[1] 段红娟[1] 刘江昊[1] 毕玉保[1] 王军凯[1] 郑扬帆 张海军[1] GE Shengtao;TAN Cao;DUAN hong/uan;LIU Jianghao;B;WANG Junkai;ZHENG Yangfan;ZHANG Haijun(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室

出　　处：《硅酸盐学报》2018年第6期813-817,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金面上项目(51472184);湖北省教育厅高等学校优秀中青年科技创新团队计划(T201602);湖北自然科学基金创新群体项目(2017CFA004)

摘　　要：以SiO_2及活性炭粉为反应物、Mg粉为还原剂、NaCl-KCl二元盐为反应介质,采用熔盐镁热还原法低温制备了SiC纳米粉体,并采用TG–DSC非等温氧化法对所合成SiC纳米粉体的氧化动力学进行了研究。结果表明：所合成SiC纳米粉体的主晶相为2H-SiC;合成2H-SiC的最佳工艺条件为n（C）和n（Si）摩尔比为1.3：1.0,Mg粉过量60%（质量分数）、反应条件为1 373 K保温3 h时合成粉体中2H-SiC的相对含量最高约为72%,所合成SiC的晶粒大小约为20~50 nm。Kissinger法和Ozawa法的计算结果表明：所合成SiC纳米粉体的氧化反应表观活化能分别约为267.96和270.33 kJ/mol。SiC nano-powder was synthesized via a molten-salt-mediated magnesiothermic reduction method in NaCl-KCl molten salt using silicondioxide, activated carbon and magnesium powders as raw materials. The oxidation kinetics of prepared SiC nano-powder were analyzed by thermogravimetry-differential scanning calorimetry. SiC powder with crystalline sizes of 20–50 nm and 2H-SiC content of 72%（mass fraction） can be synthesized under the optimum condition（i.e., 1 373 K, 3 h, C and Si molar ratio of 1.3, and the excess Mg amount of 60%）. The apparent activation energies of SiCnano-powder calculated based on the Kissinger and Ozawa methods are respectively 267.96 kJ/mol and 270.33 kJ/mol.

关 键 词：2H-碳化硅 纳米粉体 熔盐镁热还原 氧化动力学 

分 类 号：TB35[一般工业技术—材料科学与工程]