AVAILABLE IN MANY FORMS
Future Alloys can provide the Highest Quality Copper Tungsten / Elkonite materials in many forms including:
Copper Tungsten Block, Rod, Bar, Strip, Sheet, Plate, Wire, Cube, Crucibles and Ingots.
We can supply be-spoke sizes and our sales team have many years of experience and can offer you technical information and advice for all the materials we deal with.
CUSTOM MACHINING
Do you have a special application for Copper Tungsten / Elkonite that needs custom machining?
Special cutters, feeds and cutting fluids are essential to complete Copper Tungsten machining without a detrimental effect to the material.
Future alloys have all the experience and equipment necessary to precision machine Copper Tungsten to the highest specifications.
Please be as specific as possible, for example:
“Please quote for 8 off, 30mm diameter pure copper tungsten rods, in 1m lengths”
Tungsten Copper (WCu) has outstanding resistance to wear and electrical and thermal conductivity, plus excellent resistance to erosion from electrical arcing. Copper-tungsten is able to maintain these properties at high temperatures. The mix of Tungsten and copper is varied dependent on the application required. Generally, as the percentage of the conductive copper metal increases, contact resistance decreases and electrical and thermal conductivity increase, but erosion through wear increases. Conversely as the Tungsten metal content increases, the alloy becomes harder, denser and wear resistance increases, however electrical conductivity decreases.
CHEMICAL COMPOSITION & PROPERTIES
| Name | Copper | Impurity | Tungsten | Density (g/cm³) | Hardness HB | Resistance (µΏcm) | Conductivity IACS/ % TRS / Mpa |
| CuW (50) | 50 + 2.0 | 0.5 | Balance | 11.85 | 115 | 3.2 | 54 |
| CuW (55) | 45 + 2.0 | 0.5 | Balance | 12.30 | 125 | 3.5 | 49 |
| CuW (60) | 40 + 2.0 | 0.5 | Balance | 12.75 | 140 | 3.7 | 47 |
| CuW (65) | 35 + 2.0 | 0.5 | Balance | 13.30 | 155 | 3.9 | 44 |
| CuW (70) | 30 + 2.0 | 0.5 | Balance | 13.80 | 175 | 4.1 | 42 |
| CuW (75) | 25 + 2.0 | 0.5 | Balance | 14.50 | 195 | 4.5 | 38 |
| CuW (80) | 20 + 2.0 | 0.5 | Balance | 15.15 | 220 | 5 | 34 |
| CuW (85) | 15 + 2.0 | 0.5 | Balance | 15.90 | 240 | 5.7 | 30 |
| CuW (90) | 10 + 2.0 | 0.5 | Balance | 16.75 | 260 | 6.5 | 27 |
Name: Copper Tungsten / Elkonite
Copper-tungsten or WCu alloy also known as trade names Elkonite®, is a composite matrix of tungsten and copper, which combines the excellent properties of the elements, such as heat resistance, ablation resistance, low thermal expansion, and excellent thermal and electrical conductivity. One of tungsten’s key properties is the ability to maintain its strength at high temperatures, while the copper proportion increases the electrical and thermal conductivity of the composite.
The result is a hard, durable, long-lasting material with excellent resistance to erosion from electrical arcing, outstanding resistance to wear, and excellent electrical and thermal conductivity. Copper-tungsten is able to maintain these properties at high temperatures. This makes it ideal for electrical contact applications which require high arc resistance combined with good electrical conductivity.
There are two fundamental tungsten copper manufacturing methods:
Powdered Metallurgy:
A blend of fine powders of copper, tungsten and various binding materials is formed under high pressure, and then sintered at high temperatures.
Infiltration:
Copper-tungsten is produced by infiltrating copper into a tungsten skeleton under high temperature and high pressure.
There are a range of materials available with varying proportions of copper and tungsten, the typical range being 50 to 90% tungsten and 50 to 10 % copper. The more tungsten that is used in the mix, the harder and denser is the alloy, the more copper that is used, the better is the electrical and thermal conductivity.
Tungsten Copper (WCu) alloy is used in a wide range of applications including electrodes for resistance welding and electrode discharge machining (EDM), medium and high voltage arcing contacts for electrical switchgear, heat sinks for electronic devices, furnace components, high voltage discharge tubes, balance weights, dies for castings, heat spreaders, microwave carriers, heating elements, chip carriers, substrates and frames for power and semiconductor devices and many others. Applications include:
Tungsten copper composites are widely used for contacts in switchgear, vacuum contactors, circuit breakers, transformer tap changers, vacuum load switches, and protective atmosphere contactors.
Copper tungsten and copper tungsten carbide offer low-cost alternatives to silver tungsten and silver tungsten carbide when utilised in non-oxidizing conditions. Vacuum as well as oil and gas filled devices often use copper tungsten contacts. In air switching applications, the material is often used for arcing contacts or where there is enough contact force to break through the oxides formed.
The mix of Tungsten and copper is varied dependent on the target application. Generally, as the conductive copper metal increases, contact resistance decreases and electrical and thermal conductivity increase, but contact erosion and contact sticking or welding become more of an issue. Conversely as the refractory metal content increases, contact wear decreases and there is less chance of the contacts sticking or welding.
CuW50 and CuW55 mixes have the lowest tungsten content. They are a good selection for switching and contact materials for oil filled systems. CuW55 is also utilised for arcing contacts in oil circuit breakers and arcing edges of selectors and switchblades in transformer tap changers.
CuW65 and CuW70 are used as contact materials in severe arcing applications including gas, oil and some types of air circuit breakers. They are also used for arcing edges on selectors and reversing switch blades.
CuW75 and CuW80 are used as contact materials under extreme arcing conditions. Typical applications include arcing contacts in gas and oil circuit breakers, contactors and transformer tap changers, arcing plates and arc runners in power switching equipment.
CuW85 and CuW90 have the highest tungsten content. They are used as contact materials where resistance to contact welding, sticking and arc erosion are the most important factors. They also provide adequate heat and current interruption capabilities. Typical applications are power vacuum switches and high power spark gap electrodes, etc.
Tungsten-copper materials are utilised for arcing contacts in SF6 type circuit breakers for medium and high voltage applications. Copper-tungsten arcing contacts are used within the switching chamber and exposed to extreme thermal and mechanical stress during operation. At the point of arcing, for fractions of a second, temperatures can elevate up to 19,000 degrees C.
Copper Tungsten (WCu) alloys are used widely for EDM (Electrical Discharge Machining) and ECM (Electrochemical Machining) electrodes.
Tungsten-copper is an excellent material for Electrical Discharge Machining (EDM) electrode materials in applications for which wear resistance and cutting stability are crucial. While Graphite is generally a widely used material for EDM electrode materials, copper tungsten is the material of choice when processing contours with fine detail, precise geometries and sharp corners, such as small holes, narrow slots and small ribs.
Copper tungsten electrodes have a higher melting point and resistance to wear than graphite electrodes and therefore longer life cycles and more accurate production of detail. The end result being precise components with an excellent surface finish. Copper tungsten electrodes can be used to erode virtually any type of parts and it is highly recommended for eroding nickel super alloys, tungsten carbide, and other exotic materials.
Electrochemical Machining (ECM) is a technique used to remove metal by an electrochemical process. It is useful for processing extremely hard materials or designs that are complicated in shape and difficult to machine using conventional methods. ECM can cut fine details such as intricate contours or cavities, small or odd-shaped angles in hard and exotic metals. Both internal and external geometries can be machined. It can only be applied to work electrically conductive materials.
ECM is often categorized as “reverse electroplating”, because it removes material instead of adding it. It is also used used as an effective deburring process.
High metal removal rates are possible with ECM, with no thermal or mechanical stresses being transferred to the part, and high quality mirror surface finishes can be achieved.
In the ECM process, copper-tungsten withstands the erosive effects of short circuit malfunctions far better than other materials.
Resistance welding is a liquid state thermo-electric welding process in which heat is generated at the interface surfaces of welding plates due to electric resistance and a controlled low pressure is applied to these plates to create a weld joint. It is named as resistance welding because it uses electrical resistance to produce heat.
There are four main type of resistance welding; Spot Welding; Seam Welding; Projection Welding; and Flash Butt Welding. Tungsten-copper makes an ideal electrode material as it combines the strength, high density and high melting point of tungsten with the excellent electrical properties and resistance against DC arcing of copper. It is typically used for spot welding electrodes, flash and butt welding electrodes, electro-forming and electro-forging electrodes facings for upsetting of studs and rivets, cross wire welding of large diameter wire and rod, light upsetting and seam welding bushings.
Copper tungsten electrodes can be machined using high speed steel cutting tools, tungsten carbide cutting tools and standard grinding wheels.
Refractory metal resistance welding electrodes are divided into classes from 10 to 14 by the Resistance Welder Manufacturers Association (RWMA) with classes 10, 11 and 12 representing composites of copper and tungsten. Below is a general guide on usage for RWMA classes of tungsten copper group B electrodes:
Class 10 Copper Tungsten
Generally for flash and butt welding electrodes requiring good electrical and thermal conductivity is and where a degree of malleability is desired.
The proportion is a powder metallurgical blend of 45% copper and 55% of the refractory metal tungsten. The combination produces hard, dense alloy of superior wear resistance and strength at higher temperatures. Plus they have good thermal and electrical conductivity.
Class 11 Copper Tungsten
Ideal for flash and butt welding electrodes, projection welding electrodes, light upsetting and seam welding bushings. It is harder than Class 10 and used where moderate pressure is required. This material can also be used for spot welding low conductivity steels such as stainless steel.
The powder metallurgical blend is 25% copper and 75% of tungsten. The combination produces dense, hard metals of superior wear resistance and strength at higher temperatures. Plus they have good thermal and electrical conductivity.
Class 12 Copper Tungsten
Suitable for heavy duty projection welding electrodes, electro-forging and electro-forming, and electrodes facings for upsetting of studs and rivets, cross wire welding of large diameter wire and rods.
The powder metallurgical blend is 20% copper and 80% tungsten. This combination produces hard, dense metals of superior wear resistance and strength at higher temperatures. Plus they have good thermal and electrical conductivity.
Tungsten-copper is used for shaped charge liners with typically 70-90% tungsten and 10-30% copper compositions.
A shaped charge liner is an explosive charge shaped to focus the energy of the explosive. Their are used for nuclear weapons, armour penetrating munitions and industrial explosive and penetration applications.
Cone shapes are most commonly used, having an internal apex angle of 40 to 90 degrees. Different apex angles yield varying distributions of jet mass and velocity. Other widely used shapes include ellipses, tulips, hemispheres, trumpets, and bi-conics.
Liners have historically been made using many different materials. The deepest penetrations are achieved with a dense, ductile metal, and a very common choice has been copper. The selection of the material depends on the target to be penetrated; for example, aluminum has been found effective in penetrating concrete targets.
Pure metals are used for the deepest penetrations because they possess the greatest ductility, hence delaying the breakup of the stretching jet into pieces.
In some applications however, such as charges for oil well applications, tungsten alloy shaped charge liners are essential so that a solid slug or carrot not be formed, since it would plug the hole just penetrated and stem the flow of oil. Therefore in the petroleum industry, liners are generally fabricated by powder metallurgy to yield jets that are composed mainly of dispersed fine metal particles. The penetration of tungsten copper is enhanced by a factor of 1.3 against copper for steel targets, as both the density and the break up time are increased. This is perfect for the oil well completion process.