Tungsten-copper Electrical Contact Material

Electrical contact materials play an important role in instruments and electrical switches. With the development of high-voltage power transmission and transformation to large capacity and ultra-high voltage, the improvement of automation level and sensitivity of low-voltage power distribution system and control system, as well as the renewal of electronic industrial products, have put forward new requirements for electrical contact materials.

In order to improve the functional structure of W-Cu electrical contact materials, the researchers used powder metallurgy liquid phase sintering method to add a small amount of titanium, nickel and rare earth into the manufacturing process, which includes the following steps:

1)Take tungsten powder, titanium carbide powder, nickel powder, lanthanum chloride powder, copper powder, and mix the raw materials with SZ-100 Y mixer for 3 hours to get the mixture.

2)Put the mixture in the GCr15 steel mould, press it on Y-630T hydraulic press, control the pressing pressure to 200 MPa, and get the blank with diameter of 20 mm.

3)Put the blank into the graphite mould, use Ar gas as protective gas, sinter in JR-50-160 high-temperature sintering furnace at 1200 C for 6 hours, and get the rough product. Mechanical processing is carried out according to the requirements, and tungsten-copper electrical contact material is obtained.

Using powder metallurgy liquid phase sintering method, W powder forms W skeleton in liquid phase sintering; TiC powder disperses into W-Cu matrix to improve the melting resistance of materials; Ni powder plays a role in improving wettability and fluid fluidity; CeCl₃ or LaCl₃ can play the role of sintering flux, while improving the adhesion strength of two phases, it can reduce the Cu-Ni alloy. The viscosity of the melt can reduce the sintering temperature.

The density, conductivity and hardness of W-Cu electrical contact materials prepared by this method are more than 98.0%, 26-65% IACS and 102-265HBS respectively.

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