Up-scalable preparation of nano zirconium carbide powder in liquid polymeric precursor and its pyrolysis mechanism
Up-scalable preparation of nano zirconium carbide powder in liquid polymeric precursor and its pyrolysis mechanism
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DOI：
10.1016/j.ceramint.2021.10.095
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发表时间：
2021-10
影响因子：
5.2
通讯作者：
Lin Zhao;Xueying Wang;S. Lee;E. Ionescu;R. Riedel
中科院分区：
文献类型：
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作者：
Lin Zhao;Xueying Wang;S. Lee;E. Ionescu;R. Riedel
采用液体聚合前驱体法制备纳米ZrC粉体。将正丁醇锆（Zr(OnBu)4）和苯甲酰丙酮（BA）以不同摩尔比直接混合，合成透明液态碳化锆单源前驱体。通过添加不同量的BA可以改变前驱体中的碳含量。当BA/Zr(OnBu)4摩尔比为4.6:1时,得到X射线纯ZrC。在不添加溶剂的情况下，前体的粘度非常低（<8 mPa s）。碳化锆粉末是通过在氩气中在 800°C 下热解，然后在真空中在不同温度下加热进行碳热还原反应来制备的。分析了所制备的 ZrC 粉末的热解行为、相组成和转变以及微观结构。由于热解过程中有机组分的分解和蒸发以及ZrO2向ZrC的转化而释放出CH4、CO和CO2气体，导致总共60-70%的质量损失。合成的 X 射线纯 ZrC 粉末的平均晶粒尺寸小于 30 nm。同时推导了纳米碳化锆粉末的热解机理。
Nano size ZrC powder was prepared by liquid polymeric precursor method. Zirconium n-butoxide (Zr(OnBu)4) and benzoylacetone (BA) were mixed directly with different molar ratios to synthesize transparent liquid zirconium carbide single-source precursors. The carbon content in the precursor could be changed by adding different amount of BA. X-ray pure ZrC was obtained when the molar ratio of BA/Zr(OnBu)4was 4.6:1. The viscosity of the precursor was very low (<8 mPa s) without the addition of solvents. Zirconium carbide powders were fabricated by the pyrolysis at 800 °C in argon and subsequent heating at various temperatures in vacuum for carbothermal reduction reaction. The pyrolysis behavior, phase composition and transformation, and microstructure of the as-fabricated ZrC powders were analyzed. The gases of CH4, CO and CO2released due to decomposition and evaporation of the organic component and transformation from ZrO2to ZrC during pyrolysis resulted in total 60–70% mass loss. The average grain size of the synthesized X-ray pure ZrC powders was less than 30 nm. Meanwhile, the pyrolysis mechanism of nano zirconium carbide powder was deduced.