WC-Co复合粉形貌遗传特性及粒度分布研究

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。

Study on Genetic Characteristics of Morphology and Particle Size Distribution of WC-Co Composite Powder

Using ammonium metatungstate, soluble cobalt salt, and organic carbon source as the raw materials, the WC-Co composite powder was fabricated by spray conversion, calcinations and low temperature reduction-carbonization methods. The phase composition, grain size of WC, powder morphology, particle size distribution of precursor powder and composite powder were characterized. Results show that the composite powder was composed of WC and Co phases, The grain size of WC was about 60nm; the appearance of precursor powder was a kind of spherical shell structure, some of them are broken; powder morphology was not changed after calcinations; particle surface produces a large number of pore, the powder morphology was similar with precursor powder, genetic characteristics of morphology was fine; The mean grain size of composite powder was smaller than precursor powder and the particle size distribution was narrow; The mean particle size was increased with the increase of the slurry concentration, liquid feeding rate and with the decrease of centrifugal speed, but the particle size changes slightly with different inlet temperature.