Tungsten carbide vacuum sintering furnace

In tungsten carbide, carbon atoms are embedded in the interstices of the tungsten metal crystal lattice without damaging the original metal crystal lattice, forming an interstitial solid solution, so it is also called an interstitial (or intercalation) compound. Tungsten carbide can be prepared by heating a mixture of tungsten and carbon at high temperature. The presence of hydrogen or hydrocarbon can accelerate the reaction. If tungsten is used for the preparation of oxygen-containing compounds, the product must finally be vacuum-treated at 1500 ° C to remove the carbon oxides.

Two basic methods for sintering cemented carbides: one is hydrogen sintering-one controls the component composition through the kinetics of phase reaction in hydrogen and atmospheric pressure; the other is vacuum sintering,which applies vacuum environment or reducing ambient gas pressure controls the composition of the cemented carbide by slowing the reaction kinetics. Vacuum sintering has a wider range of industrial applications. Sometimes, sintering hot isostatic pressing and hot isostatic pressing are also used for the material. These technologies have an important impact on the production of cemented carbide.

Hydrogen sintering: Hydrogen is a reduction atmosphere, but when hydrogen reacts with the sintering furnace wall or supporting device, it will change other components and provide a suitable carbonization potential to maintain the thermodynamic equilibrium with the cemented carbide. In traditional cemented carbide sintering, the carbon content of carbides in the mixture should be adjusted to a theoretical value, and this value should be maintained throughout the entire hydrogen sintering process. For example, when sintering 94WC-6C0 cemented carbide, the carbon content is 5.70 to 5.80% (mass fraction) when entering the furnace, and it should be maintained at 5.76 + 0. 4% when the furnace is released.

Tungsten carbide crystal structure

Vacuum Sintering Furnace Technical Parameter :