Analysis of Tungsten Copper Contacts

Like tungsten silver (WAg) contacts, tungsten copper (WCu) contacts are a typical tungsten contact. Since both tungsten silver and tungsten copper contacts are based on refractory metal tungsten, their physical and chemical properties, production methods and uses are basically similar. It should be noted that the price of silver will be more expensive than that of copper.

Take tungsten copper contact as an example, it is an electrical contact with tungsten as the base and copper as the auxiliary material. It is a pseudo-alloy product composed of two elements, tungsten and copper. .

From the perspective of physical and chemical properties, WCu contacts combine the characteristics of tungsten and copper, which are mainly manifested in high melting point, high density, high hardness, good plasticity, low thermal expansion coefficient, good high temperature resistance, strong corrosion resistance, and electrical and thermal conductivity. Good resistance to arc burnout and welding resistance. It is worth mentioning that when the temperature rises above 3000°C, the copper in the WCu contacts will be liquefied and evaporated, absorbing a lot of heat energy, so it has the effect of sweating and cooling. In addition, the conductivity and plasticity of WCu contacts are generally better with increasing copper content.

In terms of production methods, WCu contacts can be prepared by infiltration method, copper oxide powder method or injection molding method. The steps of the infiltration method: first press the tungsten powder into a shape, then sinter it into a tungsten skeleton, and finally infiltrate the copper element. The steps of the copper oxide powder method: first reduce the copper oxide powder to copper powder, and then sinter with tungsten powder. The copper forms a continuous matrix in the sintered compact, and the tungsten is used as a strengthening framework. The steps of injection molding method: firstly mix nickel powder, copper tungsten powder and tungsten powder of different sizes, then add organic binder for injection molding, and then remove the binder for sintering.

In terms of use, tungsten copper contacts are important components of high-voltage circuit breakers, ultra-hydraulic switches, isolating switches, earthing switches, circuit breakers and other products.