How is ultrafine tungsten carbide powder produced

       

As a professional manufacturer of tungsten carbide powder, wococarbide.com is here to talk to you about the preparation technology of tungsten carbide powder. I believe it will be helpful to everyone.

 

Tungsten carbide powder production process

 

The general preparation method of tungsten carbide powder is the carbothermic reduction method. The tungsten powder is prepared first, and the tungsten oxide (usually yellow tungsten and blue tungsten) is reduced. The specific process is: mixing tungsten powder and carbon powder, The furnace body is heated, and the two are synthesized into tungsten carbide powder at an appropriate temperature. There are many furnace bodies to choose from, mainly carbon tube furnaces and high-frequency induction furnaces. However, this method has limitations. The manufactured tungsten carbide powder is of micron level and cannot be further refined. In recent years, the preparation technology of tungsten carbide powder has been fully researched and developed, and many nano-sized powder preparation technologies have been applied, such as direct reduction carbonization technology, plasma method, mechanical alloying technology, gas phase carbonization method, etc.

Figure (1) Tungsten carbide powder sintering furnace

The specific production method of tungsten carbide powder is as follows:

1. Direct carbonization reduction method

The direct carbonization reduction method is an effective method to obtain finer powders. It also extracts tungsten from tungsten oxide and directly carbonizes it.

2. Mechanical alloying method

Mechanical alloying is usually also called high-energy ball milling, which refers to the synthesis of powders that are difficult to obtain by traditional methods at room temperature through the mechanical driving force and shearing force under high-energy ball milling.

3. Plasma method

A common way to prepare ultra-fine powder is the plasma method. Metal tungsten powder or tungsten oxide powder can be used as the raw material for this method, but the selected carbon is gas, mainly CH4 or C2H2 gas.

4. Gas phase carbonization method

Gas phase carbonization must first obtain the corresponding gas phase, mainly the gas phase of the required metal element, and then react with the corresponding gas at a certain temperature, mainly the metal gas phase and the carbon-containing gas react, carbonization occurs and metal compounds are generated. Nano powder can be obtained after the temperature is lowered.

 5. Freeze-drying method

This method is a more promising method for preparing tungsten carbide powder. The first step is to prepare a metal salt solution containing tungsten (usually tungstate series), and then mix and stir the solution evenly. At this time, the temperature of the solution is rapidly cooled, and then the frozen material is cooled by a Roots pump or a mechanical pump. The surrounding pressure is reduced to below the four-phase equilibrium point, and then the temperature is increased, and the solid solvent in it is sublimated to obtain a sponge-like dry product. The dry product is taken out and calcined to obtain nano-scale metal tungsten powder. Tungsten carbide powder.