用气流粉碎分级法对超细WC粉末研磨

The application of jet mill in powder metallurgy industry

超细硬质合金具有高硬度、高耐磨性的优异性能,保证超细硬质合金的晶粒度小而且均匀的一个关键因素就是以粒度细小、分布均匀的超细W C粉末为原料。在超细W C粉末的制备过程中,对从氧化物还原、碳化后得到的W C粉末的后续处理非常重要,目前普遍采用的是球磨粉碎,但是经过机械方法粉碎后的超细粉末,很难使物料达到所需粒度要求,产品往往处于一个较大的粒度分布范围。文中讨论了一种新型的粉碎技术——气流粉碎分级技术,它兼有气流粉碎和气流分级,使得到的粉末在气流粉碎下细化、在气流分级下减小其粒度分布。气流粉碎分级技术是当今世界原材料加工技术的重要方面,将其应用于超细硬质合金的制备中有很重要的实际意义。

Ultrafine cemented carbide demonstrates a superior combination of higher wear resistance and higher hardness.The key factor to obtain ultrafine carbides with pure,fine and homogeneous grain is using finer tungsten carbide powder with uniform particle size distribution.During the process of manufacturing ultrafine WC powder,post processing of WC powder plays a important role which was made by the reduction and carburization tungsten oxide.At present,current method of post processing WC is ball milling,which cannot obtain high quality powder for the limitation of this kind of mechanical processing,whose product usually have loose particle distribution.A new kind of pulverizing technology has been investigated,namely jet mill grinding,which is a typical grinding-classification process.In the flow of the turbo-air,large particle was pulverized,thus,a powder with tight particle distribution was obtained.The jet mill grinding is a paramount technology in the area of powder processing,and of great significance in the manufacture of high quality ultrafine carbides.