内凝胶工艺结合碳热氮化法制备ZrN纳米粉体

Preparation of ZrN Nanopowders by Internal Gelation and Carbothermic Nitridation

摘要:

采用内凝胶工艺制得无定形的氧化锆凝胶与炭黑均匀混合的前驱体粉末,获得的前驱体在氮气条件下进行碳热氮化处理后得到氮化锆(ZrN)纳米粉体。结合热重/差式扫描量热分析(TGA/DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等手段,对内凝胶前驱体的热处理行为、所得产物的物相组成、微观形貌及显微结构等进行了表征。研究结果表明,氮化温度的升高有利于氮化程度的提高,1400℃氮化温度下可得到纯相纳米ZrN粉体；此外,碳的引入在热处理过程中起到了必要的还原作用,且碳的加入量需要适当,C/Zr摩尔比接近2是获得纯相ZrN粉体产物较为合适的条件。

Abstract:

Zirconium nitride (ZrN) nanopowders were prepared by carbothermic nitriding of precursor in flowing nitrogen. The precursor was mixture of zirconia gel and carbon black which was obtained by using internal gelation process. The heat treatment behavior of the precursor material, phase composition, morphology and microstructure of powder products were characterized by simultaneous thermogravimetric analysis and differential scanning calorimetric analysis (TGA/DSC), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). With increase in temperature, nitriding level increased. Pure ZrN phase was achieved at 1400°C and the particle size of the powder product was in nanometers. Carbon plays an important role of reductant in nitridation process and the carbon to zirconium mole ratio should be properly controlled to ~2 such that desired ZrN products could be prepared.