What Is Tungsten Copper Contact

Tungsten copper contact is subjected to extreme mechanical and thermal stresses during operation. For fractions of a second, temperatures rise to several thousand degrees as a result of the arcing. Our tungsten copper alloy electrode materials are used because of tungsten copper alloy electrode unique physical properties. Tungsten copper alloy electrode material offered by us is high quality. We can provide all kinds of tungsten copper electrode as your requirements. Tungsten copper electrode is easy to be machined.

Advantages

Tungsten Copper Contact Picture

Pure tungsten and copper, tungsten copper electrode uniform material, low content of gas and impurity, very high burn-off resistance, excellent thermal and electrical conductivity, all necessary joining and machining processes. 

1, High arc resistance combined with good electrical conductivity 

2, High thermal conductivity

3, low thermal expansion

4, Special tungsten copper alloy products are available at customers' requests 

Applications

1, Arcing contacts and vacuum contacts in high and medium voltage breakers or vacuum interrupters

2, Electrodes in electric spark erosion cutting machines

3, Heat sinks as passive cooling elements of electronic devices

Properties

1, Material: 50-90% Tungsten / 50-10% Copper

2, Density: 11.80~ 16.80 g/cm3

3, Conductivity (IACS %): 54~27

4, Resistivity: 3.0~6.5 µΩcm

5, Techniques: Copper unfiltered Tungsten block in vacuum high-temperature stove.

If you have any inquiry concerning tungsten copper products, please do not hesitate to e-mail us by : sales@chinatungsten.com

Tungsten Copper Contact for Air Breaker

Tungsten copper contact for air breaker is an important component in low-voltage distribution network and electric drive system, which can prevent it from overloading based on contacting and breaking circuit.When the general overload circuit, the overload current can not make the electromagnetic release of action, but can make the heat element to produce a certain amount of heat, to promote the bimetal heating up bending, push the lever to hook and lock release, the tungsten copper The main contact breaking, cut off the power. When the line short-circuit or serious overload current, short-circuit current exceeds the instantaneous trip setting current value, the electromagnetic release to produce a large enough suction, the armature to attract and hit the lever, so that the hook around the shaft seat rotation and lock release, The buckle under the action of the reaction force spring will be three main contact breaking, cut off the power.

According to different applications, tungsten copper air breaker can be divided into main contact, auxiliary contact and alarm contact.

Main contact: In the event of a serious overload or short circuit fault, the coil in series with the main circuit will produce a strong electromagnetic attraction to the armature to attract the top of the open hook, so that the main contact disconnected. When the power supply voltage returns to normal, it must be re-closed to work, which achieves the pressure loss protection;

2. Auxiliary contact: It is the circuit breaker main circuit point, a mechanical linkage on the mechanical contact, mainly for the circuit breaker sub-state display, connected to the circuit breaker control circuit through the circuit breaker of the separation, the implementation of related electrical control or interlock;

3. Alarm contact: Mainly used for the circuit breaker load overload short circuit or other fault free tripping.

Tungsten Copper Contact for SF6 Breaker

Tungsten copper contact for high-voltage breaker is kind of oil-free switchgear that uses SF6 gas as arc quenching medium and insulating medium. It has better performance in arc extinguish and insulation than oil circuit breaker and has high requirement of application, management, operation of SF6. So it main used for the voltage level of 110kv.

It composed of porcelain column structure: It also known as blocks, a plurality of identical unit interrupters and pillar insulators can be used to form the circuit breakers of different voltage levels. The circuit breaker consists of three independent single-phase and one hydraulic, electrical control cabinet. Each phase consists of two pillars of porcelain sets of four interrupters (fracture) in series. In each pillar porcelain top of the unit is equipped with two unit interrupter, 120 ° angle V-shaped arrangement, the two parallel capacitors are arranged horizontally.

Tank structure: Using the advantages of box-type multi-oil circuit breaker, the circuit breaker and the transformer together, compact structure, anti-seismic and anti-fouling ability. It is generally three-phase split-type, single-phase from the base, insulated porcelain casing, current transformers and single-break interrupter with the shell composition. Each phase is equipped with a hydraulic mechanism and a control cabinet which can be operated individually and can be operated in three phases by means of electrical control.

Characteristic

1. As insulating gas, SF6 has many advantages, is colorless, tasteless, non-toxic, non-flammable inert gas and has performance in cooling arc. Especially cooling effect under high arc temperature;

2. The chemical effect of SF6 gas itself is very stable, and has a very high dielectric strength;

3. Blocking effect: give full play to the effect of air blowing arc, interrupter small size, simple structure, breaking current, arc time is short, breaking capacitor or inductor current without re-ignition, over-voltage;

4. Long electrical life: 50kA full capacity of continuous breaking up to 19 times, the cumulative breaking current up to 4200kA, maintenance cycle is long, suitable for frequent operation;

5. Good sealing performance: SF6 gas has lower water content, arc chamber, resistance and pillar into separate air separation, on-site installation without opening, after installation with automatic connection; installation easy maintenance, and to prevent dirt and moisture Into the circuit breaker inside.

Tungsten Copper Contact — Ultrasonic NDT

Tungsten copper contact is also known as tungsten copper electrical contact or tungsten copper contact tip, which is a kind of psudoalloy that consist of W and Cu two kinds metals of immiscible and without the formation of intermetallic compounds. Consequently, it not only has high hardness, high melting point, high strength, low coefficient of thermal expansion and excellent wear resistance and corrosion resistance of W, but also has perfect electrical and thermal conductivity and plasticity of Cu. And it has been played an important role in some high-voltage switch, breaker, and instrument components.

Currently, preparation of tungsten copper contacts is mainly used in PM (powder metallurgy) technology, the corresponding method used for the performance testing, such as the density, the hardness, the strength, the tensile strength and micro-structure, etc., will have some damages on the integrity of tungsten copper products and lead to failure. And these tools to test for products in large quantities can only do a certain proportion of sample, which is difficult to have some representation. If the unqualified tungsten copper contacts undetected used in actual production is likely buried security risk, both for production or personal safety is extremely unfavorable. So the relevant researchers use Non-destructive testing techniques to measure and evaluate the mechanical properties of tungsten copper related products.

Ultrasonic NDT (Non-destructive Testing) is a kind of process that ultrasound can penetrate deep into the use of a metallic material, by entering a cross-sectional another cross-sectional; edge reflection occurs at the interface characteristics of the parts to check for defects. When the ultrasonic beam from the surface of the part by the probe pass to the metal inside encounter defects and Part underside of the reflected wave occurs, respectively, form a pulse waveform on the screen, based on these pulse waveforms to determine the location and size of the defect. Compared with other detecting methods, Ultrasonic NDT has many advantages, such as:

1. Ultrasound has perfect penetration ability, low transmission loss and the probing depth of up to several meters;

2. High sensitivity, it can be found with the diameter of the air-based reflectance 0.1-1mm equivalent reflector;

3. Accurate positioning, to assume the shape and the size are also more accurate;

4. Convenient in operation and it is suitable for the most materials;

5. The entire testing process will not cause environmental pollution, no harm to the human body completely.

Tungsten Copper Contact HIP Process

Tungsten copper contact has excellent electrical, thermal conductivity and chemical stability, but the problem in densification is always a barrier in its developing way. And this incomplete densification will have an bad influence on the hardness, the strength, wear resistance and arc ablation resistance conversely. So the relevant researchers propose that pressure sintering, a total reduction of chemical and explosive compaction method special process to improve the density of tungsten copper contact material. However, there are some defects in these processes, such as high operation and maintenance costs, be suitable for the parts with small size and so on.

In order to improve the properties of tungsten copper contacts, we combine tungsten copper contact used in high voltage circuit breakers to study HIP process for tungsten copper material impact, and its elimination of the porosity, densification mechanism and related factors. HIP (Hot Isostatic Pressing), it places the product into a closed container, which is applied to each peer pressure while applying heat, under the action of high temperature and pressure, the product can be sintered and densified. HIP has many advantages, such as combines the advantages of hot pressing with isostatic pressing, lower molding temperature, excellent densification and performance, which is essential for high-performance material manufacturing; now, in the United States, Japan and Europe to achieve the industrial, marine, aviation, aerospace, automotive and other fields have been widely used.

Before HIP process, tungsten powder mixed with a certain amount of copper, cold isostatic pressing, low temperature pre-sintered to give semi-finished copper by infiltration. It uses argon (Ar) as pressure transmission medium, temperature control (tungsten-rhenium thermocouple measurement), pressure, dwell time and other relevant parameters, before and after the HIP process copper tungsten contact material hardness, density, bending strength and conductivity of comparative measurements. The density uses conventional Archimedes drainage method; the hardness uses Rockwell hardness HRB and refers to Brinell hardness HB; flexural strength is measured by GB electrical contact material basic performance; electrical conductivity is measured by eddy current conductivity tester.

The experimental result shows that HIP densification mechanism of tungsten copper contacts is similar to the cast alloy, which removes internal defects by deformation - closed - diffusion under high temperature and high pressure and achieves completely densification. Therefore, it requires after-infiltrated material should have good closure, all internal defects, osteoporosis and so can not in communication with the outer surface. If all the defects can not be guaranteed enclosed inside the blank in the process of infiltration, the density after HIP process changes little, even no change. In addition, HIP treatment effect is also related to the content of copper. When the HIP temperature reaches a temperature close to the melting point of copper, its surface will be leaking copper beads phenomenon. Overall, HIP process can promote tungsten copper contact completely densification, which remarkably improves the mechanical and physical properties, and effectively solves dispersion and reliability.

If you have any interest in our tungsten copper alloy products, please do not hesitated to contact us by Email:sales@chinatungsten.comor by telephone:86 592 5129696, we are at your service.

Fiber-structure Tungsten Copper Contact

Tungsten copper is a psudoalloy, which is composed of two kinds of immiscible and has a great difference in physical and chemical properties metals. Since it has both advantages of W and Cu (high hardness, high strength, excellent corrosion resistance of W, excellent electrical and thermal conductivity of Cu) so that it has a broad application prospect in high-pressure, high-load vacuum circuit breaker and microelectronics fields. Due to the special nature of tungsten copper material itself, it is basically prepared by PM (Powder Metallurgy) process, but also for this reason that makes the structure and properties of tungsten copper alloy products subject to certain restrictions.

In order to make the organizational structure of tungsten copper contact more reasonable, the relevant researchers made many attempts in recent years, such as PIM (Powder Injection Molding), functionally graded materials, nano-structure and W-Cu tungsten fiber reinforced composite structure. Here we focused on the preparation of the fibrous structure of tungsten copper contacts and analyze the factors that affect performance and ablative infiltrated. The use of vacuum infiltration process, and select netting lamination to tungsten as weft, warp knit copper-dimensional net. Under vacuum condition, liquid copper has better liquidity and there is no air in the pores, which is more conducive to liquid copper fill-in. Tungsten braided copper mesh (copper as the infiltration time of induction of copper) and copper billets, and then the two stacked together in a vacuum sintering furnace infiltration, and sintered copper above the melting point (about 1300 ℃).

Copper in the molten state infiltrated in pores of tungsten skeleton by capillary forces, thereby connected to each other and form a dense material integrally. The advantage of using this method is that tungsten wire can distribute uniformly and copper wire can effectively induce. Since the most difficult to achieve tungsten copper contact with fiber-structure is how to make the fibers uniformly distribute in the matrix, whose distribution will affect the final properties directly. The weaving process can control tungsten wire to adjust the spacing between fibers. In addition, the distribution of copper wire at a high temperature infiltration, which presents the liquid copper supplement, under the action of surface tension, integration can reduce the surface area, prompting tungsten copper contact materials densification.

Tungsten wire diameter, infiltrated temperature and time all have an effect on the process. It uses tungsten fiber to take place of tungsten powder of conventional PM. Too large granularity of tungsten powder will have segregation and appear large area Cu-rich region, the binding force between the tungsten particles is also poor; too small granularity will prone to accumulate, leading to difficult to form a passage between the capillary and even hinder the formation of closed-cell infiltration were, so that the anti-arc erosion capacity decreases dramatically.

Fiber-structure has straight route so its density is higher after infiltration. But with the decreasing fiber diameter, it easily to form when copper was infiltrated pointed or wedge-shaped space, and solidification resistance is also large so that the defect forms. In addition, infiltration temperature has an optimum range, below the temperature which the sintered skeleton strength decreases, and the extension of sintering time, decrease the efficiency and increase energy consumption; the high temperature which the copper was in favor of lowering the viscosity of infiltration, but on the other hand the surface tension of liquid copper is reduced, and has an adverse effect on infiltration.

If you have any interest in our tungsten copper alloy products, please do not hesitated to contact us by Email:sales@chinatungsten.comor by telephone:86 592 5129696, we are at your service.

Tungsten Copper Contact Microwave Sintering

Except conventional sintering process, microwave sintering as a new sintering process is also gradually began to apply in the tungsten copper material. It uses special microwave band has the fine structure coupled with a basic material to generate heat, and material dielectric loss in the electromagnetic field of the material as a whole it is heated to the sintering temperature to achieve densification. Microwave sintering has many advantages, such as volumetric heating, heat conduction from the inside out and stepwise temperature distribution within the high outside low, which are beneficial for heating rate, sintering time and energy efficiency. For powder metallurgy industry, it is essential that lower cost of production and lower energy consumption, so microwave sintering has a broad prospect in tungsten copper contact.

Tungsten copper (W-Cu) contact is a kind of psudoalloy that consist of W and Cu immiscible and with a great difference in the melting point, which means it is difficult to achieve higher density by conventional sintering method and it has a bad influence on the electrical and thermal conductivity, hermeticity and other mechanical properties. Compared with conventional sintering process, microwave sintering can effectively improve the density of tungsten copper contact materials to improve the microstructure and increase other comprehensive performance.

From microwave sintering temperature and holding time point of view, the sintering temperature rises to a certain temperature, density tungsten copper contact materials increases, the relative density of up to 99.8%, close to fully densification. This is due to the temperature rise reduces the wetting angle, improved copper solution on a solid phase wettability of tungsten, reducing the resistance of the particle rearrangement process, the particles rearrangement sufficiently improve the densification rate. Meanwhile, temperature increases can also reduce the viscosity of liquid copper and increase in liquid copper capillary force mobility, which will be conducive to densification. But thereafter the temperature increased, lower relative density decreased, which is due to the reduced coefficient of viscosity, the effect of gravity copper deposited on the bottom of the fluid will gradually lead to the formation of a new gas into the pores, thereby reducing the density.

The sintering additive also has a great impact on the tungsten copper contacts sintering densification. The experiments show that adding a small amount of Co, Ni can significantly improve the solubility of W, and help to improve the ability of densification. In the liquid phase sintering process, W in solid solution reacted with sintering aid or intermediate phase. And the product will form a continuous layer of wrapping on W grains surface, which can significantly reduce the surface tension between the liquid and the copper particles W and improve wettability of the two phases.

In addition, copper liquid under the action of capillary force, the gap between the W particle flow and cause a rearrangement of W particles, thereby significantly promoting compact shrink compact. However, copper liquid flow too often will lead to the emergence of copper accumulation pool, even reduce the uniformity of the sample. Overall, by analyzing the experimental data, in the manufacture of tungsten copper alloy contact process, the microwave sintering technology compared to conventional sintering has a significant advantage in heating rate and sintering cycle; sintering additive selection can promote the densification of tungsten copper contacts；samples of microwave sintering has more uniform microstructure and better mechanical properties.

If you have any interest in our tungsten copper alloy products, please do not hesitated to contact us by Email:sales@chinatungsten.comor by telephone:86 592 5129696, we are at your service.

Tungsten copper contact

Tungsten copper contact is also called tungsten copper point. Tungsten copper contact is widely used in high voltage applications where there requires highly repetitive switch.

Tungsten has a high melting point, which gives tungsten excellent arc-corrosion resistance. Tungsten copper contact is a combination of copper and tungsten. Tungsten copper contact is a cost efficient relay contact and can resist arcing and corrosion. While tungsten copper contact should be regularly cleaned and burnished.Tungsten copper contact is suitable to be used in the circuit.

Tungsten copper contact can be made from tungsten copper rod or tungsten copper disk.

As for quality, we double-check materials before beginning production. We also conduct stringent inspections to ensure durability and specifications to meet your requirements.Buyers from US and India come to us for tungsten and molybdenum products and we have cooperated for over 10 years. Our selection and services satisfy clients worldwide.

If you have any interest in our tungsten copper alloy products, please do not hesitated to contact us by email:sales@chinatungsten.com or by telephone:86 592 5129696, we are at your service.