碳氢协同还原-碳化法制备纳米WC粉的工艺及机理

发布时间：2018-03-12 06:23

  本文选题：碳氢协同还原　切入点：纳米碳化钨　出处：《稀有金属材料与工程》2017年01期 　论文类型：期刊论文

【摘要】：针对传统还原-碳化工艺中WC粉颗粒长大的问题,采用碳氢协同还原-碳化法制备纳米级球形WC粉,研究了前驱体配碳比和反应温度对WC粉性能的影响。结果表明,WC粉的碳含量与前驱体的配碳比密切相关,最佳配碳比(即n(C)/n(W)值)为3.6。W转变为WC具有结构遗传性,WC粉的平均粒径与还原温度和碳化温度密切相关。随着还原温度由680℃升高至800℃,还原水蒸气与碳反应生成CO和H_2,显著降低体系中水蒸气的分压,从而抑制中间产物W颗粒的挥发-沉积长大,WC粉的平均粒径随还原温度升高而减小。碳化过程中的高温促进WC颗粒的晶界迁移和纳米W颗粒之间的烧结合并长大,WC粉的平均粒径随碳化温度的升高而增大。n(C)/n(W)为3.6的前驱体粉末经800℃还原和1100℃碳化后,得到平均粒径为87.3 nm的球形WC粉。
[Abstract]:Aiming at the problem of WC powder particle growing up in traditional reduction-carbonization process, nano-sized spherical WC powder was prepared by means of carbon-hydrogen synergistic reduction-carbonization method. The effects of precursor carbon ratio and reaction temperature on the properties of WC powder were studied. The results show that the carbon content of WC powder is closely related to the carbon ratio of the precursor. The average particle size of WC powder transformed into WC with structural heredity is closely related to the reduction temperature and carbonation temperature, with the reduction temperature rising from 680 鈩，

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