制备纳米WC的热力学分析

Thermo-dynamics Analysis of Synthesis Nano-WC

以钨粉为钨源,酚醛树脂(PF)为碳源,采用溶胶-凝胶法制备碳化钨(WC)。通过X射线衍射、扫描电镜对样品进行表征。从热力学系统分析W氧化物的还原过程,WC的合成过程,以及碳化时间和碳化温度对产物的影响。结果表明:钨的化合物主要是由H2还原成钨单质,其形成过程为WO3→WO2.9→WO2.72→WO2→W;WC的形成过程为W2C→WC→W2C。

The nano-tungsten carbide particles were prepared using sodium tungstate as tungsten source and phenol formaldehyde resin （PF） as carbon source by sol-gel. X-ray diffraction （XRD）, scanning electron microscopy （SEM） were used to characterize the samples and the precursors. The factors which can affect the samples, including carbonization time and carbonization temperature,and W oxide reduction process, WC synthesis process were systematically investigated by thermo-dynamics. The results show that tungsten oxide can change into tungsten mainly by H2 following as WO3→WO29→ WO2.72→WO2→W; the forming process of WC is W2C→WC→W2C.