以偏钨酸铵、可溶钴盐、有机碳为原料,经喷雾转化、煅烧、低温还原碳化制备WC-Co复合粉。对前驱体、复合粉物相组成、WC晶粒度、微观形貌、平均粒度及分布进行研究。结果表明:复合粉由WC和Co两相组成,WC晶粒度约为60 nm;前驱体粉末呈空壳球形结构,部分颗粒破裂;经煅烧后,形貌未发生明显变化;再经还原碳化处理,颗粒表面产生大量孔隙,形貌与前驱体相似,具有很好的形貌结构遗传特性;复合粉平均粒度比前驱体略有减小且粒度分布更窄;溶液浓度、给料速度越大,离心转速越小,则平均粒度越大;进气温度对粒度影响很小。
Using ammonium metatungstate, soluble cobalt salt, and organic carbon as the raw materials, the WC-Co composite powder was fabricated by spray conversion, calcinations and low temperature reduction-carbonization. The phase composition, grain size of WC, powder morphology and particle size distribution of precursor powder and composite powder were characterized. Results show that the composite powder is composed of WC and Co phases, and the grain size of WC is about 60 nm. The appearance of precursor powder is a kind of spherical shell structure, some of which are broken. Powder morphology does not change after calcinations. After reduction and carbonization, a large number of pores are produced on particle surface, the powder morphology is similar to that of precursor powder, and genetic characteristics of morphology is fine; the mean grain size of composite powder is smaller than that of precursor powder and the particle size distribution is narrow; the mean particle size increases with the increase of the slurry concentration as well as liquid feeding rate and the decrease of centrifugal speed, but the particle size changes slightly with different inlet temperatures.