碳源对喷雾转化法制备WC-Co复合粉末的影响

发布时间：2018-02-10 09:23

  本文关键词： 超细WC-Co复合粉末 喷雾转化法 有机碳 炭黑 原位还原碳化 酸浸蚀　出处：《功能材料》2017年11期 　论文类型：期刊论文

【摘要】：以偏钨酸铵、醋酸钴、有机碳源或炭黑经喷雾干燥后的前驱体粉末为原料,在N2气氛中进行原位还原碳化,制备超细WC-Co复合粉末。采用DSC研究还原碳化过程中的相变过程,并用XRD分析不同工艺下复合粉末的物相组成,利用SEM分析复合粉末经磷酸浸蚀前后的微观形貌,结合纳米测量软件测量浸蚀前后晶粒粒度分布。结果表明:2种碳源的粉末在低于900℃的温度下可发生还原反应,以有机碳为碳源的粉末较炭黑的还原温度低。在950℃的碳化温度条件下,炭黑为碳源的复合粉末所需要的碳化时间长,制备得到的晶粒大,WC的晶粒度为0.29μm,WC-Co复合粉末二次颗粒是由金属钴粘结细小的碳化钨晶粒而成。有机碳制备的晶粒细小并且较均匀,WC的晶粒度为0.16μm,碳化钨晶粒间会形成烧结颈,经过磷酸浸蚀后,其烧结颈结构不会破坏。
[Abstract]:Ultrafine WC-Co composite powder was prepared by in-situ reduction and carbonization of ammonium metatungstate, cobalt acetate, organic carbon source or carbon black after spray drying in N _ 2 atmosphere. The phase transition in the process of reduction and carbonization was studied by DSC. The phase composition of the composite powder was analyzed by XRD, and the microstructure of the composite powder was analyzed by SEM before and after etching with phosphoric acid. The grain size distribution before and after etching was measured with nano-measurement software. The results showed that the powder of two kinds of carbon sources could be reduced at a temperature below 900 鈩，

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