Tungsten-Copper Contact

Like tungsten-silver (WAg) contacts, tungsten-copper (WCu) contacts are also a typical type of tungsten contact. Since both tungsten-silver and tungsten-copper contacts are products based on refractory metal tungsten, their physicochemical properties, production methods, and applications are fundamentally similar. It should be noted that the price of silver is generally higher than that of copper.

Taking tungsten-copper contacts as an example, they are electrical contacts primarily composed of tungsten with copper as an auxiliary material, forming a pseudo-alloy product made of tungsten and copper elements, known in English as tungsten copper contact.

In terms of physicochemical properties, WCu contacts combine the characteristics of tungsten and copper, including high melting point, high density, high hardness, good plasticity, low thermal expansion coefficient, excellent high-temperature resistance, strong corrosion resistance, good electrical and thermal conductivity, and superior resistance to arc erosion and welding. Notably, when the temperature exceeds 3000°C, the copper in WCu contacts liquefies and evaporates, absorbing significant heat and providing a “sweating cooling” effect. Additionally, as the copper content increases, the electrical conductivity and plasticity of WCu contacts typically improve.

In terms of production methods, WCu contacts can be prepared using infiltration, copper oxide powder, or injection molding methods. The infiltration method involves pressing tungsten powder into a shape, sintering it to form a tungsten skeleton, and then infiltrating it with copper. The copper oxide powder method involves reducing copper oxide powder to copper powder, then sintering it with tungsten powder, where copper forms a continuous matrix and tungsten acts as a reinforcing framework. The injection molding method involves mixing nickel powder, copper-tungsten powder, and tungsten powder of varying sizes, adding an organic binder for injection molding, and then removing the binder and sintering.

In terms of applications, tungsten-copper contacts are critical components in high-voltage circuit breakers, ultra-hydraulic switches, isolating switches, grounding switches, circuit breakers, and other products.

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