摘要
以ZrO_2纤维、B_2O_3粉、Mg粉为原料,分别以NaCl、MgCl_2及NaCl、MgCl_2复合盐为稀释剂,采用模板辅助燃烧合成法,经酸洗制备了ZrB_2短纤维,采用试算法计算了反应体系绝热温度,并对产物进行XRD和SEM表征。结果表明:反应体系的绝热温度随着熔盐掺量的增加而降低,掺NaCl体系绝热温度下降较为明显,尤其是在熔盐掺量较高的情况下。加入NaCl后产物物相主要为ZrB_2以及少量残余的ZrO_2,加入MgCl_2后产物中还有少量Mg_3B_2O_6。加入熔盐不仅能避免ZrO_2纤维的熔融,使产物更容易保持原料中纤维的形状,还能减小产物的晶粒尺寸,加入MgCl_2能促进产物晶粒的发育,随着MgCl_2掺量的增加,纤维上的颗粒逐渐发育成棱角分明的六方状晶体。从残余的ZrO_2含量和晶粒尺寸分析,单盐的效果要优于复合盐,MgCl_2的效果优于NaCl。
The short ZrB 2 fibers were synthesized by template assisted combustion synthesis, taking ZrO 2 fibers, Mg and B 2O 3 as raw materials, NaCl, MgCl 2 and their compound salts as diluents. The adiabatic temperature of the systems was calculated by trial method. The effects of molten salt content on the phase composition and micromorphology of the products were investigated by XRD and SEM, respectively. The results showed that the adiabatic temperature decreased with the increment of molten salt content. The adiabatic temperature drop of the system with NaCl was more obvious, especially in high molten salt content condition. The NaCl added samples comprised of ZrB 2 and small amounts of residual ZrO 2. Small amount of Mg 3B 2O 6 was found in the sample added with MgCl 2. The addition of molten salt could prevent the ZrO 2 fibers from melting and make it easier for product to maintain the shape of original fiber. The crystallite size of the product could be reduced by NaCl and MgCl 2 in the systems. MgCl 2 could promote the crystallization of ZrB 2 and they grew into the hexagon crystals of clear boundaries with the increasing content of MgCl 2. From the analysis of residual ZrO 2 and grain size, the effect of single salt was superior to compound salt, and MgCl 2 was more effective than NaCl.
作者
肖国庆
周盼
丁冬海
XIAO Guoqing;ZHOU Pan;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)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第22期3875-3879,3890,共6页
Materials Reports
基金
国家自然科学基金(51502236,51572212,51772236)
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
关键词
ZrB2纤维
熔盐
燃烧合成
ZrB 2 fiber
molten salt
combustion synthesis
