冷冻干燥法制备超细镍粉的研究  

PREPARATION OF ULTRAFINE NI POWDER BY FREEZE DRYING

作　　者：翟立力[1] 席晓丽[1] 聂祚仁[1] 蒋亚宝[1] 童培云[1] 

机构地区：[1]北京工业大学材料学院,北京100022

出　　处：《粉末冶金工业》2006年第3期10-13,共4页Powder Metallurgy Industry

基　　金：教育部全国优秀博士学位论文作者专项基金资助项目(200030);国家高技术研究发展计划资助项目(2002AA322010);教育部高校青年教师奖励计划资助项目(第三届)

摘　　要：以NiSO4、NaOH为原料,以液氮为冷冻介质,采用冷冻干燥法制备了粒度小于100 nm的超细镍粉;并采用X射线衍射、扫描电镜对冻干前驱体、还原粉末的中间状态和末状态的物相及转变过程进行了分析。研究结果表明:冷冻干燥前驱体呈非晶态,为棒条状,表面光滑。从冻干前驱体到超细镍粉的转变过程是,首先从非晶棒条前驱体的尖端、棱等比表面能较大的地方开始,并逐步还原吞噬前驱体,生成了球形超细镍粉。在本研究中,冻干前驱体的形貌对最终产物的粒度影响不大。The ultrafine Ni powder with an average size less than 0.1μm was prepared by freeze drying form the NiSO4 and NaOH. The phase and the transformation from precursor to final Ni powder were studied by mean of XRD and FESEM. The result showed that the precursor before freeze drying is amorphous with a smooth surface and club - shaped. The transformation begins with the precipitation of spheroid Ni powder at the tip and edges of the precursor, and the ultrafine Ni powder develops at the expense of precursor. The morphology of precursor does not affect the final powder size.

关 键 词：冷冻干燥 Ni粉 还原 晶化 

分 类 号：TF123.7[冶金工程—粉末冶金]