Ultrafine Tungsten Carbide Powder Reduction Method

Ultrafine cemented carbide is a tool material developed in recent years. It is mainly based on ultrafine tungsten carbide powder and adds appropriate binder (such as Co) and grain growth inhibitor to produce high hardness, high wear resistance and high toughness cemented carbide material. Its performance is higher than conventional cemented carbide. It is used in hard-to-machine metal materials tools, micro-drills in electronic industry, precision dies and dies. Medical dental drills and other fields have shown more and more extensive application prospects.

By optimizing the program, the researchers found an effective method to prepare ultra-fine tungsten carbide powder. The program is as follows:

(1)Passivation of ultrafine tungsten powder: the surface of ultra-fine tungsten powder is passivated by filling pure carbon dioxide gas into the ultra-fine tungsten powder; and (2) Carbon distribution: the passivated ultra-fine tungsten powder and carbon powder are loaded into the carbon blender, cooling water, mixed with inert gas protection, and then cooled naturally after mixing;

(2)Carbonization: the mixed ultra-fine tungsten powder and carbon powder are carbonized in the high temperature of the furnace to synthesize massive tungsten carbide powder; (4) grinding and sieving: the massive tungsten carbide powder is loaded into the grinder and crushed, and then the tungsten carbide powder is obtained after cooling and sieving.

The above-mentioned method is to passivate raw material ultrafine tungsten powder with pure carbon dioxide gas at first. In the following steps, cooling water is used to reduce powder temperature and surface activity by introducing inert gas. The contact between precursor and air is avoided. The oxidation and spontaneous combustion reaction of precursor formed by ultrafine tungsten powder and carbon powder are prevented. The quality of products is improved and material loss is reduced. The mixing amount of ultrafine tungsten powder and carbon powder is 1-2 times that of the traditional method, which improves the production efficiency.