What kind of tungsten oxide can produce high quality cemented carbide?
At present, there are yellow tungsten oxide, blue tungsten oxide and violet tungsten oxide which are available in the market. Which kind of raw material is most suitable for cemented carbide production? Violet Tungsten oxide is the best raw material for producing superfine tungsten powder and nanometer metal tungsten powder. Ultrafine tungsten carbide was prepared by ultrafine or nano tungsten powder, and then cemented carbide was produced, the properties and requirements of cemented carbide are better than those made of ordinary. tungsten powder. The alloy with violet tungsten as the raw material has better quality and stronger adaptability, and the violet tungsten can make the penetration capability of the military armour piercing bullet increase by 20%, and the abrasion resistance of the carbide cemented carbide tool can be increased by 12%, etc.
The preparation methods of violet tungsten include hydrogen reduction, reverse hydrogen reduction, and liquid ammonia reduction. No matter what kind of reduction, it needs to be carried out in the high temperature reduction furnace. The reduction temperature is between 790 and -900 degrees centigrade. It is generally believed that the optimum reduction temperature of violet tungsten is between 800°C-850°C. In the pusher type reducing furnace environment, the temperature band range from800 - 850°C is generally set. The thickness of the loading layer can not be too large, and the flow of hydrogen should be controlled properly. The reduction reaction of violet tungsten not only on the surface, but also in the internal reduction process.
The crystal structure of violet tungsten is generally needle shape and micro rod-like crystal shape. It is generally believed that the tungsten powder prepared by the violet tungsten oxide of the needle crystal is finer, while the tungsten powder made by the rod shaped crystal violet tungsten oxide is relatively coarse. Of course, if it is the other crystal form or color, the reduction failure can be basically determined.
In summary, violet tungsten oxide has the advantage of manufacturing ultrafine tungsten powder, tungsten nano powder, and preparation of ultrafine tungsten carbide hard alloy for final production, in addition, violet tungsten is a high quality precursor material for gas sensitive element, but again, violet tungsten does not apply doping, doped work should apply to blue tungsten oxide.