硼砂对自蔓延高温合成ZrB_2粉体的影响  

Effect of Na_2B_4O_7 on ZrB_2 Powder Prepared by Self-propagating High-temperature Synthesis

作　　者：张薇[1] 肖国庆[1] 丁冬海[1,2,3] ZHANG Wei;XIAO Guoqing;DING Donghai(College of Materials and Mineral Resources,Xi’an University of Architecture and Technology,Xi’an 710055;Postdoctoral Mobile Research Station of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055;State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039)

机构地区：[1]西安建筑科技大学材料与矿资学院,西安710055 [2]西安建筑科技大学材料科学与工程博士后流动站,西安710055 [3]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,洛阳471039

出　　处：《材料导报》2017年第24期125-128,144,共5页Materials Reports

基　　金：国家自然科学基金(51272203;51572212);中国博士后基金(2016M602940XB);先进耐火材料国家重点实验室开放课题

摘　　要：以ZrO_2、Mg、B_2O_3及Na_2B4O_7为原料,采用自蔓延高温合成技术制备ZrB2粉体。通过FactSage7.0软件计算,从热力学角度研究了该反应体系发生自蔓延反应的可能性。采用X射线粉末衍射物相分析仪、场发射电子扫描电镜-能谱分析对最终产物的物相组成及显微形貌进行检测。分析结果显示,过量的Mg、B_2O_3可有效提高产物中ZrB_2的含量,Mg和B_2O_3分别过量40%(质量分数)、30%(质量分数)为Mg-ZrO_2-B_2O_3体系的较佳配比。基于上述优化配比,研究了用无水硼砂(Na_2B_4O_7)替换原料中B_2O_3对产物ZrB_2含量及晶粒尺寸的影响,当替换量达到15%(质量分数)时,ZrB_2的含量最高,并且随着Na_2B_4O_7替换量的增加,产物的晶粒尺寸由2μm减小至不足0.5μm。ZrB2 powders were prepared by the self-propagating high-temperature synthesis(SHS)using ZrO 2,Mg,B 2O 3 and Na 2B 4O 7 as main raw materials.Based on thermodynamic calculation,the feasibility of the SHS was studied by FactSage7.0.The phase composition and microstructure of the final product were characterized with X-ray diffraction(XRD)and field-emission scanning electron microscopy(FESEM)with energy dispersive spectrometer(EDS).The ZrB 2 purity of the final product could be improved when the raw materials were mixed with extra amount of Mg and B 2O 3,it was found that the optimum extra amounts of Mg and B 2O 3 were 40wt%and 30wt%,respectively.Based on the optimum ratio,the effect of replacing B 2O 3 by Na 2B 4O 7 on purity and microstructure of ZrB 2 was studied.When the replacement ratio was 15%,the purity of ZrB 2 was the best,the grain size of ZrB 2 decreased from 2μm to less than 0.5μm with the increasing Na 2B 4O 7 replacement ratio.

关 键 词：自蔓延高温合成 镁热还原 ZrB2粉体 

分 类 号：TQ174[化学工程—陶瓷工业]