Views:4 Author:Site Editor Publish Time: 2021-08-10 Origin:Site
Ultra-fine cemented carbide is mainly made of ultra-fine tungsten carbide powder (WC) as the basic raw material, and is synthesized by adding appropriate binders and grain growth inhibitors. It has high hardness, high wear resistance and high toughness, etc. Features, widely used in micro-drills, precision molds, medical dental drills and other fields. How to prepare superfine WC powder?
A preparation method of ultrafine WC powder includes the following steps:
(1) Passivation of ultra-fine tungsten powder: Fill the ultra-fine W powder with pure carbon dioxide gas and let it stand to passivate the surface of the ultra-fine tungsten powder; (2) With carbon: passivated ultra-fine tungsten powder The carbon powder and the carbon powder are charged into the carbon distributing machine, the cooling water is cooled, and the inert gas is introduced to protect the mixture, and then the mixture is naturally cooled; (3) Carbonization: The mixed ultrafine tungsten powder and carbon powder are carbonized and synthesized at a high temperature in a carbonization furnace Lump tungsten carbide powder; (4) Crushing and sieving: Put the lump tungsten carbide powder into a pulverizer for pulverization, and sieving after cooling to obtain WC powder.
The precautions for this production method are:
(1) In the passivation of ultra-fine W powder, the tungsten powder is filled with pure carbon dioxide gas and left for more than 12 hours to passivate the surface of the powder and prevent spontaneous combustion.
(2) In the carbon blending process, cooling water is used to cool the barrel wall of the carbon blending machine continuously to reduce the temperature of the precursor of superfine W powder and carbon powder. In addition, the precursors of tungsten powder and carbon powder can also be continuously filled with inert gas to avoid contact of materials with air.
(3) In the crushing and sieving, the crushed WC powder can be sieved after cooling with cooling water. In addition, it can also be filled with inert gas and sieved to protect the ultrafine powder.
Compared with the traditional production method, the ultrafine tungsten carbide powder produced by the preparation method is less susceptible to spontaneous combustion, has a lower oxygen content, and has a higher production efficiency.