Tungsten-copper composite material is a two-phase structure pseudo-alloy composed mainly of tungsten and copper elements, which is a metal matrix composite material. Due to the great difference in physical properties between copper and tungsten, it cannot be produced by melting casting method, and powder alloy technology is generally used for production.
Tungsten-copper alloys are widely used in aerospace, aviation, electronics, electric power, metallurgy, machinery, sports equipment and other industries. Secondly, it should also be used to make the contact of arc ablation resistant high-voltage electrical switch, rocket nozzle throat liner, tail rudder and other high-temperature components. It is also used as the electrode of electrical processing, high-temperature mold and other occasions that require electrical conductivity and thermal conductivity and high-temperature use.
Molybdenum tungsten copper or copper powder mixed after forming, in 1300-1500 ° liquid phase sintering. The material prepared by this method has poor uniformity and many closed voids, and the resulting density is usually lower than 98%. However, the sintering activity can be improved by adding a small amount of nickel to the activated sintering method, mechanical alloying method or oxide reduction method to prepare ultra-fine and nano powder, so as to improve the density of tungsten-copper and molybdenum-copper alloys. However, nickel activation sintering can significantly reduce the conductivity and thermal conductivity of the material, and mechanical alloying can also reduce the conductivity of the material by introducing impurities. It is difficult to prepare powder by oxide co-reduction method because of complicated process and low production efficiency.
Tungsten powder or molybdenum powder is pressed into shape, and burned into tungsten and molybdenum skeleton with certain porosity, and then melted into copper. This method is suitable for tungsten copper and molybdenum copper products with low copper content. Compared with tungsten-copper, molybdenum copper has the advantages of small mass, easy processing, linear expansion coefficient, thermal conductivity and some main mechanical properties, etc.
Although heat resisting property is inferior to tungsten copper, but better than a few heat resisting material, because this applies foreground better. Because the wettability of molybdenum copper is worse than that of tungsten copper, especially when the molybdenum copper with low copper content is prepared, the density of the material after melting and seepage is low, which leads to the material's air tightness, electrical conductivity and thermal conductivity cannot meet the requirements, and its application is limited.
