Chemical formula: WC. Black hexagonal crystal, metal luster, high hardness similar to that of diamond, good conductor of electricity and heat. Melting point: 2,870℃; boiling point: 6,000℃; relative density: 15.63(18℃). Tungsten carbide is insoluble in water, hydrochloric acid and sulfuric acid, but is freely soluble in the mixture of nitric acid and hydrofluoric acid. Pure tungsten carbide is fragile; but its fragility can be reduced if a small amount of titanium, cobalt and other metals are added. Titanium carbide, tantalum carbide or their mixture is frequently added into tungsten carbide applied to steel cutting tools, to improve its anti-explosion capacity. Tungsten carbide has stable chemical properties.
In tungsten carbide, carbon atoms are embedded into the metal lattice spacing of tungsten, and do not damage the original metal lattices, to form interstitial solid solutions; therefore, they are also called interstitial (or insertion) compounds. Tungsten carbide can be prepared by heating tungsten and carbon mixtures at high temperature, with the reaction accelerated due to the existence of hydrogen or hydrocarbon. If tungsten oxygenated compounds are used for preparing tungsten carbide, the product must be subjected to vacuum treatment at 1,500℃ finally, to remove carbon and oxygen compounds. Tungsten carbide is suitable for machining at high temperature, and can be used for manufacturing cutting tools, kiln structured materials, jet engines, gas turbine engines, nozzles, etc.
Application to production of various alloys
▲Application to the production of high-speed cutting turning tools, kiln structure materials, jet engine parts, metal ceramic materials, resistance heating elements and so on in large quantity.
▲Application to the manufacturing of cutting tools, wear-resistant parts, smelting crucibles made of copper, cobalt, bismuth and other metals, as well as wear-resistant semiconductor films.