Tungsten copper alloy have a variety of types, different types have different characteristics, so that it can be used in different products.

1. Tungsten copper electrical materials: Mainly divided into electrical contact and electrical processing materials.

1)Electrical contact material: It is one of the most important kinds of electrical materials with high resistance to arc erosion and welding resistance, as electrical contacts, electrical contacts and electrodes in instrument, applicable to all kinds of high and low voltage switchgear. The maximum amount of tungsten copper material containing 20% to 40%, electrical contacts is the largest class, the utility model is mainly used for medium, high voltage and high current switching devices.

2) Electrical material: Refers to the electrode and mold materials used in resistance welding, electric riveting and electric upsetting. Using more tungsten copper materials for meeting the requirements of EDM, ensure the machining accuracy.

2. Armor materials: Tungsten copper materials can be used as armor material, also known as liner. This type of liner was first made of red copper and was widely used. It should improve the penetration ability in order to increase the cover unit quality, Develop unit quality of tungsten cutting liner material which is larger than copper. In an ideal situation, it is about 30% higher than the penetration ability of copper. Use it to make a cup or funnel, inversion in the front end of a cartridge, depending on the temperature and pressure of the powder, the cover is changed to form a jet.

3. Instantaneous high temperature material: It can be used at temperature close to the melting point of tungsten and slightly above the melting point of tungsten, it is an important and special tungsten copper which can complete the mission in a few seconds to 200 seconds. The most important properties of the instantaneous high temperature materials are ablative and thermal shock resistance, this material is mainly used for the manufacture of high temperature components of spacecraft, such as the rocket nozzle, the direction of the guided missile and other components of the rudder. It has intense thermal shock damage to components.

Tungsten copper electroplating notes:

1. Tungsten copper belongs to metal powder crystallization, in order to prevent the surface of metal particles fall off and affect the electroplating effect, it should avoid strong acid and strong alkaline cleaning before electroplating.

2. Remember the accuracy of the cleaning method before the copper electroplating, cleaning agent should avoid strong acid and alkali substances, in order to enhance the adhesion of tungsten copper surface, ultrasonic and neutral cleaning solution should be used to clean the surface of tungsten copper oxide, oil and other dirty substances.

3. Electroplating after cleaning.

4. Before electroplating, it is recommended to electroplate the samples according to the electroplating process, tungsten copper was placed in the 800 vacuum furnace for heat preservation for 20 minutes.

5. After the release of tungsten copper if there is no bubble, discoloration, and other problem indicating that the electroplating process is no problem.

Precautions on the use of tungsten copper:

1.Please confirm that there are no cracks, defects or other abnormal conditions in the product.

2.Please use to strengthen vigilance, prevent falling injured hands.

Precautions on processing of tungsten copper:

1.Electrical discharge machining and wire cutting: Do not panic, this is a normal phenomenon when the tungsten copper is found to be slow in discharge and wire cutting.

2.Machining：

Tungsten copper does not have magnetism, confirm that the product has been fixed before processing.

Tungsten copper in the production of sharp corners may be damage due to impact.

Please pay attention to the strengthening of the load when the hole is drilled through the hole, avoid processing deficiencies.

Precautions on product shape:

It is normal if the product is not the same as the appearance of the product.

Tungsten copper powder size which prepared by hydrothermal synthesis of tungsten copper co reduction method meet the requirements of micro nano, and improve the sintering properties of tungsten copper. Ultimately, tungsten copper with high conductivity and high thermal conductivity was prepared.

Hydrothermal synthesis of precursor materials co reduction method for sodium tungstate and copper nitrate, preparation of tungsten oxide copper intermediate by hydrothermal synthesis, tungsten copper composite powder was prepared by hydrogen reduction, and then it was obtained by different spark plasma sintering, powders and alloys prepared by X-ray diffraction, high resolution transmission electron microscopy and scanning electron microscope for physical properties test and microstructure characterization.

Tungsten copper was prepared by direct hydrothermal synthesis for ammonium metatungstate and copper nitrate precursor for raw materials, its copper content is not loss. The precursor mixed solution was adjusted to alkaline, PH control in about 9, roasting at 550 to completely decompose the hydrolysate to oxide composite powder which is composed of WO₃, CuO and CuWO₄-x.

Tungsten copper direct sintering:

1. The mixture of tungsten and copper oxide or salt is refined by ball milling to obtain ultrafine or nano crystalline tungsten copper compound powder.

2. After sintering, mixture of ultrafine and nano crystalline tungsten copper powder was obtained by reduction in hydrogen.
3. By pressing molding and sintering to obtain fine, uniform and dense structure of tungsten copper.

Physical properties of tungsten and copper are very different and mutually insoluble. Therefore, under normal circumstances, even if temperature of tungsten copper alloy is more than melting point of copper, in the case of liquid phase, it is impossible to get high dense tungsten copper products.

Tungsten copper hot pressing sintering is the two processes of pressing and sintering, at the same time, the density be achieved under the low pressure which cannot be achieved in cold pressing sintering.

The density of tungsten copper increases with the increase of temperature in the range of 1000-1300℃, the best sintering time is 5-6 hours, the porosity is low and the density is higher, the grain growth is sufficient and the liquid diffusion is uniform.

By using hot pressing method of W-Cu functionally gradient heat sink material with nearly full density. The results show that the preparation of tungsten copper by this method, its gradient layer boundaries clear, each layer of compact structure and keep the original design components.

Tungsten copper metal injection molding: Because the tungsten copper after sintering machine is relatively difficult, it has high strength and hardness, so the powder metallurgy method can be used to produce parts. In the process of pressing, the products with large diameter and long diameter after sintering will cause deformation and size deviation. Using metal injection molding technology, not only because of the uniform flow filling mold cavity, but also can directly form a complex shape parts.

The basic process is:

1.Select the metal powder and binder to meet the requirement of forming.
2.At a certain temperature, the powder and binder are mixed into a uniform injection molding material.
The density of tungsten copper is 99%, and the content of copper is up to 10%, 15% and 20%. Adopting direct injection molding of tungsten powder,
After degreasing treatment, the relative perfect compact copper tungsten was obtained. However, due to the complex process and high cost, a large number of binders are introduced in the process. If these binders are not completely degreased in the subsequent sintering process, the properties of the materials will be greatly affected.

Tungsten copper activated liquid phase sintering:

Due to the high temperature liquid phase sintering method is not possible to obtain tungsten copper which get close to the theoretical density. The production cost is high and the complexity of the process is increased after sintering. On the basis of activated solid state sintering theory of pure tungsten, a method for preparing tungsten copper by adding micro activation elements to improve the sintering activity was produced.

Compared with the high temperature liquid phase sintering method, the sintering temperature is reduced, the sintering density increases and the sintering time is shortened. However, it need to further study of the theory and process, because the activation of the sintering process is still not perfect.

Tungsten copper activated liquid phase sintering is a method of activating liquid phase sintering by chemical activation of tungsten copper powder, which can activate the elements including Fe, Co, Ni and so on.

Activated sintering can be divided into two ways: one is to improve the activity of the powder, the other is to rely on external factors to activate the sintering process to improve the activity of powder, such as adding an activator in the atmosphere.

The liquid phase sintering process of tungsten copper can be divided into two parts: solid phase sintering and liquid phase sintering. Due to the chemical potential between the mixed powders, most of the solid phase diffusion occurs in the heating process. After the formation of the liquid phase, the densification process mainly depends on the particle rearrangement and dissolution precipitation mechanism, as well as the particle shape of the ball and particle accumulation. Because of the small solubility of the solid phase in the liquid copper, it is difficult to achieve densification.

Physical Properties of Tungsten Copper: Tungsten copper combines the advantages of tungsten and copper, melting point of tungsten is high(tungsten melting point of 3410℃, copper melting point of 1080℃),The density is large (tungsten density is 19.34g/cm³, the density of copper is 8.89/cm³),copper has superior conductivity and thermal conductivity, tungsten copper has moderate conductivity and thermal conductivity, but it has high temperature resistance, high strength, arc ablation resistance and density, the microstructure also uniform.

Tungsten copper (tungsten W=70 copper Cu=30)

hardness≥184HV

density =13.8-14g/cm3

conductivity %IACS≥42

tensile strength≥66Mpa

Softening temperature℃≥700

Tungsten copper consists of refractory tungsten and high conductivity copper, because the melting point of tungsten and copper are different and completely insoluble, so the traditional method of making tungsten copper is difficult, in order to achieve powder alloying, Many kinds of strain, defects and nano-scale microstructure were produced during high energy ball milling, the mixture of tungsten copper powder also experienced a process of repeated deformation, cold welding, grinding in mechanical alloying.

The high energy ball milling method is to find the alloyed powder and to be activated in several times by high energy ball milling, it resulting in severe plastic deformation, cold forming composite powder with lamellar structure, after processing the composite powder, the broken powder showed the atomic surface fresh prone to welding, organizational structure has been refined after the occurrence of new powder continuous welding, cold welding and fragmentation. Finally, the purpose of the realization of alloying by atomic mixing was achieved. At the same time, the grain is refined in the process of mechanical alloying, when the grain size reaches a certain degree, the surface area increases and the temperature decreases so as to obtain high uniform distribution of tungsten copper alloy powder and it is helpful to promote the alloying of powder.