刘家良，韩兵强，张锦化，陈俊峰

(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，湖北 武汉 430081)

DOI:10.13732/j.issn.1008-5548.2022.04.013

收稿日期： 2022-01-08， 修回日期：2022-05-28，在线出版时间：2022-06-23。

基金项目：国家自然科学基金项目，编号：51802232。

第一作者简介：刘家良(1997—)，男，硕士研究生，研究方向为无机非金属粉体制备与表征。E-mail:tlmalcyone@outlook.com。

通信作者简介：韩兵强(1973—)，男，教授，博士，博士生导师，研究方向为耐火材料。E-mail:hbqref@wust.edu.cn。

摘要：以二氧化钛(TiO₂)、硅粉(Si)和偏硼酸钠(NaBO₂·4H₂O)为原料，采用熔盐辅助硅热还原法制备出超高温陶瓷二硼化钛粉体(TiB₂);讨论合成温度和添加熔盐硅酸钠(Na₂SiO₃)对反应进程的影响，研究热水水洗法对副产物二氧化硅(SiO₂))去除的效果，并表征目标产物TiB₂粉体的微观形貌。结果表明：在合成温度为1 100℃、保温时间为4 h时，可以得到结晶程度高的TiB₂单晶晶粒；TiB₂粒径约为400 nm,有少部分粒径可达到1μm;在反应体系中加入Na₂SiO₃可降低体系液相的黏度，有利于对SiO₂的吸收；通过调整硅酸钠的模数，可以在常压下通过热水水洗法去除副产物，避免酸洗法对环境的污染。

关键词：熔盐；硅热还原法；二硼化钛粉体；偏硼酸钠

Abstract：Using titanium dioxide(TiO₂), silicon powder(Si) and sodium metaborate(NaBO₂·4 H₂O) as raw materials, ultra-high temperature ceramic titanium diboride powder(TiB₂) was prepared by molten salt assisted silicon thermal reduction method. The effects of the synthesis temperature and the addition of molten sodium silicate(Na₂SiO₃) on the reaction process were discussed. The removal effect of the by-product silicon dioxide(SiO₂) by hot water washing was studied and the microstructure of the target product TiB₂ powder was characterized.The results show that TiB₂ single crystal grains with high degree of crystallization can be obtained when the synthesis temperature is 1 100 ℃ and the holding time is 4 h. The TiB₂ particle size is about 400 nm and a few particles can reach 1 μm. Adding Na₂SiO₃ into the reaction system can reduce the viscosity of the liquid phase of the system, which is conducive to the absorption of SiO₂. By adjusting the modulus of sodium silicate, the by-products can be removed through the hot water washing method under atmospheric pressure, and the environmental pollution caused by pickling can be avoided.

Keywords：molten salt; silicon thermal reduction method; titanium diboride powder; sodium metaborate

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