纳米钨辅助氢气还原氧化钨制备超细钨粉  

Preparation of ultrafine tungsten powder by nano-tungsten assisting hydrogen reduction of tungsten oxide

作　　者：张勇 张国华 ZHANG Yong;ZHANG Guohua(State Key Laboratory of Advanced Metallurgy,University of Science and Technology,Beijing 100083,China)

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《粉末冶金材料科学与工程》2020年第5期375-380,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51734002)。

摘　　要：在900~1100℃温度范围内,氢气还原纯WO3粉会出现明显的W晶粒长大现象。为了有效抑制W晶粒长大,在WO3粉中添加10%~40%(质量分数)的纳米W粉辅助氢气还原氧化钨制备超细W粉。研究纳米钨添加量w(纳米W)和还原温度与时间对W粉形貌和粒度的影响,并研究影响机理。结果表明,不管是否添加纳米W,W粉粒径都随还原温度升高而增大。在没有添加纳米W粉时,由于反应过程中的CVT(chemical vapour transport,化学气相传输),很难控制产物的形核和生长,所得还原W粉的粒径为2.10~2.78μm;添加纳米W后,纳米W在反应过程中能减弱CVT并发挥形核剂的作用,从而使得W粉粒径显著减小。随w(纳米W)增加,W粉粒径逐渐减小,当w(纳米钨)为40%时,还原W粉的粒径为0.32~0.51μm。In the temperature range of 900-1100℃,the prepared W powder by hydrogen reduction of pure WO3 powder will have obvious crystal growth.In order to suppress the growth of W grains,the ultrafine tungsten powders were prepared by 10%-40%(mass fraction)nano-tungsten powder assisting hydrogen reduction of WO3.The effects of reaction temperature and the additive amount of nano-tungsten W(w(nano-W))on the morphology and particle sizes of the products were studied,and the reaction mechanism of the two methods was also discussed.The results show that whether nano W is added or not,the particle size of W powder increases with the increase of reduction temperature.Without the addition of nano W powder,it is difficult to control the nucleation and growth of the product due to the chemical vapor transport(CVT)in the reaction process.The particle size of the reduced W powder is 2.10-2.78μm.However,the addition of nano W can weaken the effect of CVT accompanied with nucleating agent in the reaction process,which makes the particle size of W powder decrease significantly.With the increase of w(nano-W)content,the particle size of reduced tungsten powder decreases gradually.When w(nano-W)is 40%,the particle size of reduced tungsten powder is 0.32-0.51μm.

关 键 词：氢气还原 超细W粉 形核和生长 化学气相传输 反应机理 

分 类 号：TF123.72[冶金工程—粉末冶金]