Tungsten copper alloy combines the advantages of metal tungsten and copper. Tungsten has a high melting point (tungsten melting point is 3410℃, copper melting point is 1080℃), high density (tungsten density is 19.34g/cm3, copper density is 8.89 g/cm3); copper has excellent electrical and thermal conductivity, tungsten copper alloy (composition generally ranges from WCu7~WCu50) has uniform microstructure, high temperature resistance, high strength, arc ablation resistance, and high density; moderate electrical and thermal conductivity, widely used in military high temperature resistant materials, electrical alloys for high voltage switches, electrical machining electrodes, microelectronic materials, as parts and components are widely used in aerospace, aviation, electronics, electricity, metallurgy, machinery, sports equipment and other industries.
1. Military high temperature resistant materials
Tungsten copper alloy is used as nozzle, gas rudder, air rudder and nose cone of missile and rocket engine in aerospace. The main requirements are high temperature resistance (3000K~5000K) and high temperature air flow scouring ability. It mainly uses the sweating refrigeration effect formed by the volatilization of copper at high temperature (copper melting point 1083℃) to reduce the surface temperature of tungsten copper and ensure its use under extreme high temperature conditions.
2. Electrical alloy for high voltage switch
Tungsten copper alloy is widely used in high voltage switch 128kV SF6 circuit breaker WCu/CuCr, high voltage vacuum load switch (12kV 40.5KV 1000A), and lightning arrester. High voltage vacuum switch is small in size, easy to maintain, and has a wide range of use. It can be used in humid, flammable, explosive and corrosive environments. The main performance requirements are arc ablation resistance, anti-fusion welding, small cut-off current, low gas content, and low thermal electron emission ability. In addition to the conventional macroscopic performance requirements, porosity and microstructure performance are also required, so special processes must be adopted, requiring complex processes such as vacuum degassing and vacuum infiltration.
3. Electrode for Electrical Discharge Machining
Early, copper or graphite electrodes were used for electrospark machining electrodes, which were cheap but not resistant to ablation, and have basically been replaced by tungsten copper electrodes. The advantages of tungsten copper electrodes are high temperature resistance, high high temperature strength, arc ablation resistance, good electrical and thermal conductivity, and fast heat dissipation. Applications are concentrated in electrospark electrodes, resistance welding electrodes, and high-voltage discharge tube electrodes.
The characteristics of electrospark electrodes are a wide variety of specifications, small batches, and large total amounts. Tungsten copper materials used as electrospinning electrodes should have the highest possible density and uniformity of organization, especially slender rods, tubes, and special-shaped electrodes.
4. Microelectronic Materials
Tungsten copper electronic packaging and heat sink materials have both the low expansion characteristics of tungsten and the high thermal conductivity of copper. Their thermal expansion coefficients and thermal and electrical conductivity can be changed by adjusting the composition of tungsten copper, thus providing tungsten copper with a wider range of applications. Since tungsten copper materials have high heat resistance and good thermal and electrical conductivity, and their thermal expansion coefficients match those of silicon wafers, gallium arsenide and ceramic materials, they are widely used in semiconductor materials. They are suitable for packaging materials for high-power devices, heat sink materials, heat dissipation components, ceramics, and gallium arsenide bases.
After research and development, the preparation technology of tungsten copper alloys has made great progress, and some new processes and technologies have been promoted and applied in production. However, in order to meet the increasing performance requirements and application needs under some special conditions, there are still some problems that need to be studied more deeply. First of all, the basic research on the forming technology of tungsten copper-based alloys should be strengthened to guide the development of new technologies. Because most of the research focuses on how to prepare high-performance alloys, while ignoring the research on basic theories, this has caused a situation where theory and process technology are out of touch. For example, in the research on the development of micro-alloyed tungsten copper-based alloys, the influence of added elements on electrical conductivity, thermal conductivity and performance needs to be further studied in order to truly provide theoretical guidance for new preparation process technologies. Throughout the development history of tungsten copper alloy materials, with the progress of basic research and the improvement of preparation technology, the performance of tungsten copper alloy has been greatly improved, which also provides a broader prospect for the expansion of the application field of tungsten copper alloy.