溶胶-凝胶法制备HfB2粉体及其氧化行为

HfB2 Prepared by Sol-Gel Method and Its Oxidation Behavior

摘要:

以HfCl4、H3BO3、酚醛树脂为原料，通过溶胶-凝胶结合碳热还原法成功制备了HfB2粉体。分别采用XRD和SEM对高温处理后的粉体相组成和微观形貌进行了分析；采用TGA研究了粉体的高温氧化行为。结果表明：处理温度及硼酸浓度的不同会导致产物纯度、颗粒大小的不同，而且高温氧化性能也有所不同。当处理温度为1800 ℃且硼酸含量高于生成硼化铪化学计量比时，产物的纯度较高，颗粒均匀，高温氧化性能较好。对溶胶凝胶结合碳热还原法制备HfB2粉体的反应机制进行了探讨

Abstract:

HfB2 powders were prepared successfully by combining sol-gel with carbonthermal reduction. The phase components and micro-structure were analyzed by XRD and SEM, respectively. The oxidation behavior of the powders at high temperature was measured by TGA. The results show that reduction temperature and content of boric acid have obvious effects on the purity, the average size and the oxidation behavior of HfB2. As the temperature is 1800 ℃ and the content of boric acid is higher than its stoichiometric ratio of the synthesizing of HfB2, the obtained HfB2 with high purity and uniform particle size has the better oxidation behavior. Moreover, the reactive mechanism of preparing HfB2 powders was also discussed