W粉球磨时间对W粉、WC粉及其制备的合金性能的影响  

Effects of Milling Time of W Powder on Properties of W Powder,WC Powder and Alloys

作　　者：阳冬元[1,2] 周春成[1,2] Yang Dongyuan Zhou Chuncheng(State Key Laboratory of Cemented Carbide, Zhuzhou Hunan 412000, China Zhuzhou Cemented Carbide Group Corp. Ltd., Zhuzhou Hunan 412000, China)

机构地区：[1]硬质合金国家重点实验室,湖南株洲412000 [2]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2016年第5期322-328,335,共8页Cemented Carbides

摘　　要：本文通过对粗、细两种W粉进行球磨,研究不同球磨时间下W粉粒度、形貌及亚晶尺寸的变化,再制备成WC及合金,观察其对WC及合金性能的影响。试验结果表明:随着W粉球磨时间的延长,细W粉中的团粒和粗W粉的聚集体先破碎或分离,随后钨晶粒在球的冲击下发生变形,特别是粗大钨晶粒中形成许多位错、裂纹等缺陷,导致亚晶尺寸不断变小。球磨后钨晶粒中存在的位错和表面裂纹在碳化开始时可有效提高碳原子向W粉颗粒内部的扩散速率,但这种影响随碳化温度提高或碳化时间的延长而不断减弱。随着W粉球磨时间的延长,其合金的磁力值均呈增加,表明合金中WC的晶粒度不断减小,但晶粒度的变化幅度不大;球磨时间对合金其它性能没有明显影响。长时间球磨粗W粉中出现少量扁平的W粉颗粒,在其制备的WC粉中也能发现,这可能是粗晶合金的金相组织中长条状晶粒数量增加的原因。Two grades of W powder with coarse and fine particles were milled, separately. The changes of the particle size, morphology and sub-grain size of the W powder under different ball milling time were tested. Then WC powder was prepared by using the W powder, subsequently cemented carbide were prepared by using the WC powder. The effects of the milling time on the properties of the WC powder and cemented carbide were observed. The results show that the aggregates in the fine and coarse W powder are firstly broken or separated along with the extension of the milling time, then the tungsten grains were deformed under the impact of the ball, especially many defects such as cracks and dislocations are formed in the coarse tungsten grains, and therefore the sub-grain size of W powder decreases with the increasing of the milling time. The dislocations and cracks of the tungsten gains can effectively improve the diffusion of carbon atom into the tungsten grains at the beginning of carbonization, but the effect is weaken with the increasing of the carbonization temperature or carbonization time. The coercive force of the cemented carbide increases with the increasing of the milling time, which indicates the WC grain size continually decreases, but the change of the WC grain size is slight. The milling time has no significant effect on other properties of the cemented carbide. A few of flat tungsten particles is observed in the W powder even in the WC powder for the coarse W powder under longer milling time, it is concluded that it results in the increasing of strip grains in coarse grained cemented carbide.

关 键 词：球磨 亚晶尺寸 W粉形貌 WC粉 性能 硬质合金 

分 类 号：TF125.3[冶金工程—粉末冶金]