Nano Tungsten-Copper Composites Conventional Preparation

Tungsten-copper composites have been widely used as electrical contact materials, electronic packaging and heat sink materials because of their good conductivity, thermal conductivity and low thermal expansion coefficient. The nano tungsten-copper composite prepared by nano-powder has excellent physical and mechanical properties.

nano tungsten-copper composites image

However, the incompatibility between tungsten and copper determines the particularity of the preparation of tungsten-copper composites. In view of the special properties and great activity of nano-particles, the preparation of nano tungsten-copper composites is particularly special. Therefore, nano tungsten-copper composites have become a research hotspot.

The conventional preparation methods of nano tungsten-copper composites mainly include the following four kinds: nano tungsten-copper composites, nano tungsten-copper composites, nano tungsten-copper composites and nano tungsten-copper.

(1)Mixed compaction sintering. This is a traditional powder metallurgy method. Firstly, tungsten powder and copper powder are proportioned in a certain proportion, then mixed, and then formed and sintered.

(2)Infiltration method. The tungsten powder or tungsten powder mixed with a small amount of copper powder is used to make compacts, and the melted copper and tungsten compacts are superimposed together. It is then sintered in a reducing atmosphere or vacuum at temperatures higher than the melting point of copper. In the sintering process, molten copper is infiltrated into tungsten skeleton by capillary action.

(3)Activated sintering. A small amount of Co, Ni, Te and Pd can be added to W and Cu systems to activate them. With the increase of activator, the activation sintering properties are improved. However, the addition of activator does great harm to the thermal conductivity and electrical conductivity of W-Cu alloy, so it is not suitable for the materials used in thermal control and electronic control.

(4)Hot pressing-sintering. Excellent properties can be obtained by pressure sintering or secondary processing after sintering. The secondary processing of W and Cu composites by hammer forging or cold-hot rolling can greatly increase the material density.

Which method can produce high quality nano tungsten-copper powder better? The application of theoretical methods mainly depends on practical experience and the strength of enterprise technicians. For example, some people think that the infiltration method has lagged behind, but there are still enterprises using this method to produce complex products with high quality and performance. Others adopt new technology and new methods with good theory, but the compactness of the finished products is poor. In a word, production needs to be adapted to the actual situation without blindly following.

 

 

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