中文摘要：

纳米碳化钨钴复合粉体具有重要的工程应用和市场发展潜力。针对纳米碳化钨钴复合粉形貌难以精确控制这一问题,本文以偏钨酸铵（AMT）、可溶性钴盐、有机碳源为原材料,以蒸馏水为溶剂,不添加WC晶粒长大抑制剂,制备钨钴碳混合溶液,再采用喷雾转化（SCP）和连续低温还原碳化法制备了纳米碳化钨钴复合粉;研究了喷雾转化过程中溶液浓度、进料速度、离心转速和转化温度4个关键因素对纳米碳化钨钴复合粉松装密度、WC晶粒度及微观形貌的影响。研究表明：通过喷雾转化法制备的纳米碳化钨钴复合粉呈空壳球形结构,Co相发生熔化使大多WC被粘结在一起,WC颗粒之间存在明显的烧结颈,颗粒表面存在大量孔隙,部分颗粒存在破裂现象;WC平均晶粒度小于200 nm;离心转速是影响粉末松装密度、WC晶粒度及颗粒形貌的最主要因素;离心转速越大,复合粉末颗粒越小,松装密度越大;同时转化温度越高,WC晶粒度越小,复合粉末颗粒越易破裂。

英文摘要：

Nanophase WC-Co composite powder has an important engineering application and large market potential. As for the problem that the morphology of nanophase WC-Co composite powder was difficult to control accurately,using ammonium metatungstate（AMT）,soluble cobalt salt,and organic carbon source as raw materials and distilled water as solvent,without adding any growth inhibitor of WC grain,the mixed solution with components of tungsten,cobalt and carbon elements was prepared,and the effects of the spray conversion process such as solution concentration,feed rate,centrifugal speed and transition temperature on the apparent density,grain size of WC and micro morphology of nanophase WC/Co composite powders fabricated by spray conversion（SCP） and low temperature reduction-carbonization methods were studied. The results showed that the appearance of composite powder was a kind of spheri-cal shell,Co phase was melted and most of the WC was bonded together; sintering neck was observed between WC particles,there were a lot of pores existing on particle surfaces,and some of the particles were broken; the mean grain size of WC was less than 200 nm; centrifuge speed was the most important factor which affected the apparent density,grain size of WC and morphology of WC/Co composite powder; the particle size of composite powder was smaller and the apparent density became bigger with greater centrifugal speed; meanwhile,the composite powder ruptured more easily and the grain size of WC became smaller with higher conversion temperature.