熔盐镁热还原法合成ZrB_2超细粉体  

Preparation of ZrB_2 Ultrafine Powders via Molten-salt-mediated Magnesiothermic Reduction

作　　者：谭操[1] 段红娟[1] 王军凯[1] 张海军[1] 刘江昊[1] 

机构地区：[1]武汉科技大学材料与冶金学院省部共建耐火材料与冶金国家重点实验室,武汉430081

出　　处：《材料导报》2017年第8期109-112,共4页Materials Reports

基　　金：973计划前期研究专项(2014CB660802);国家自然科学基金面上项目(51272188);湖北省教育厅高等学校优秀中青年科技创新团队计划(T201602)

摘　　要：为了降低ZrB_2粉体的合成温度,并在此基础上合成粒径细小、纯度高的ZrB_2粉体,以ZrO2及B4C为原料,以Mg粉为还原剂,以NaCl-KCl为熔盐介质,研究熔盐镁热还原法低温合成ZrB_2超细粉体的工艺。探讨了反应温度、B/Zr物质的量比及Mg粉用量对合成ZrB_2超细粉体的影响,并对粉体的物相组成及显微结构进行了表征。结果表明合成ZrB_2的起始温度为1 173K,最佳合成温度为1 473K。合成纯相的ZrB_2粉体最佳工艺条件为:B/Zr物质的量比为2.2,Mg过量50%(质量分数),1 473K反应3h。所合成ZrB_2粉体的晶粒尺寸为30~300nm。Phase pure ZrB_2 ultrafine powders were prepared via molten-salt-mediated magnesiothermic reduction in NaCl-KCl salt-medium using zirconium dioxide and boron carbide as raw materials,and magnesium powders as reducing agent.The influences of firing temperature,molar ratio of B/Zr and dosage of Mg powders on the synthesis of ZrB_2 were discussed,respectively.In addition,the phase composition and microstructure of the as-prepared ZrB_2 powders were characterized.The results showed that ZrB_2 could be formed at a temperature as low as 1 173 K,and the optimum synthesis temperature was 1 473 K.ZrB_2 ultrafine powders with a crystalline size range of 30-300 nm can be synthesized under the condition of 1 473K/3hreaction,B/Zr molar ratio of 2.2,and excessive Mg amount of 50wt%.

关 键 词：ZRB2 超细粉体 熔盐 镁热还原 

分 类 号：TB35[一般工业技术—材料科学与工程]