兰钨球磨对纳米钨粉团聚的影响

Effect of ball-milling on agglomeration of nanoscale tungsten powders

采用超声喷雾干燥制备的前驱体为原料,经过两阶段低温还原和球磨工艺的结合使用制备了纳米钨粉。通过还原前后粉末形貌的对比,分析了钨粉还原过程中的形貌特征。采用第一段低温还原后得到的兰钨为原料,对比了在不同阶段球磨对还原后钨粉团聚状态的影响。对所制备的纳米钨粉进行了SAXS粒度表征。结果表明:钨粉的形貌和结构具有"遗传性";兰钨阶段的球磨有效地打碎了颗粒之间的团聚,有利于颗粒之间的分散;钨粉的球磨不能打碎纳米颗粒之间的硬团聚。SAXS检测结果表明,使用两阶段还原和球磨相结合的工艺制备的纳米钨粉平均粒径为35nm。

With precursor powder prepared by ultrasonic spraying and drying process as raw material, nanoseale tungsten powders was prepared by combination of two- stage low temperature reduction process and ball - milling, By comparison of the shape of powders before and after reduction, the characteristic of shape of powder particles was analyzed in reduction. Blue tungsten oxide prepared at first - stage low temperature reduction was employed as raw materials to investigate the influence of ball - milling at different stage on agglomeration of nanoscale tungsten powders. Finally, the particle size of nanoscale tungsten powder was characterized by SAXS. The results show that the shape and structure of tungsten powders is almost the same as that of their precursor powders. The agglomeration of nanoscale tungsten powders can be broken down well if the blue tungsten oxide is ball - milled. Directly ball- milling of tungsten powder can not break down the agglomeration of nanoscale particles. The mean particle size of nanoscale tungsten powders prepared by combination of two- stage reduction and ball- milling is 35nm.