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2012年7月31日星期二

Tungsten Copper Electrical Contacts


The CuW75 tungsten copper materials can be also used in oil-filled devices, air and gas circuit breakers, contactors, and high voltage switch gear. Some common applications are: arcing contacts and platesarc runnerscurrent carrying membersblade facings.
The high electrical and thermal conductivity of tungsten copper alloy allows a cool, effective transfer of power, while the excellent arc-resistance properties of tungsten copper minimize arc erosion and transfer problems. These characteristics can be varied by composition more silver or copper yields higher electrical and thermal conductivity, while a higher refractory metal content results in superior arc erosion properties. We offer a variety of composites to meet your demands. Regardless of the environment (oil-filled devices, air and gas circuit breakers, contactors, high voltage switch gear) or the application (arcing contacts and plates, arc runners, current carrying members and blade facings), you won't be disappointed in electrical contacts made from our copper tungsten composites.

2012年7月30日星期一

Tungsten Copper Resistance Welding


If you can't stand the heat resistance welding isn't for you. Luckily, electrodes made from our tungsten copper composites perform even under the most extreme conditions. High-thermal and electrical conductivity along with the ability to reduce heat-balance problems make our tungsten copper composites excellent choices for die inserts and electrode facings, flash and butt welding dies, and hot upsetting.
The high physical and mechanical properties, as well as the thermal and electrical conductivity, of refractory metal composites make tungsten copper alloy very suitable for die inserts and electrode facings, flash and butt welding dies, and hot upsetting. They can also solve heat balance problems.

2012年7月29日星期日

Tungsten Copper Heat Sinks


Our tungsten copper composites to be used extensively in thermal mounting plates, chip carriers, flanges, and frames for high-powered electronic devices. With the thermal advantages of copper with the very low expansion characteristics of tungsten, tungsten copper has properties similar to those of silicone carbide, aluminum oxide, and beryllium oxide. The thermal conductivity and low expansion also make tungsten copper alloy an excellent choice even for extremely dense circuits.
The CuW75 tungsten copper alloy is used extensively in thermal mounting plates, chip carriers, flanges, and frames for high-power electronic devices. As a tungsten copper material, it's a composite, so both the thermal advantages of copper and the very low expansion characteristics of tungsten can be utilized.
The combination of tungsten & copper materials results in thermal expansion characteristics similar to those of silicone carbide, aluminum oxide, and beryllium oxide, used as chips and substrates. Because of tungsten copper's thermal conductivity and expansion characteristics, Tungsten copper alloy works well in densely packed circuits.

2012年7月26日星期四

Applications of Tungsten Copper


Copper tungsten alloys are used where the combination of high heat resistance, high electrical and/or thermal conductivity, and low thermal expansion are needed. Some of the applications are in electric resistance welding, as electrical contacts, and as heat sinks. As contact material the alloy is resistant to erosion by electric arc. Tungsten copper alloys are also used in electrodes for electrical discharge machining and electrochemical machining.
The CuW75 tungsten copper alloy, with 75% of tungsten, is widely used in chip carriers, substrates, flanges and frames for power semiconductor devices. The high thermal conductivity of copper together with the low thermal expansion of tungsten allows thermal expansion matching to silicon, gallium arsenide, and some ceramics.
Copper Tungsten alloy with 70-90% of tungsten is used in liners of some specialty shaped charges. The penetration is enhanced by factor 1.3 against copper for homogeneous steel target, as both the density and the break-up time are increased. Tungsten powder based shaped charge liners are especially suitable for oil well completion. Other ductile metals can be used as binder in place of copper as well. Graphite can be added as lubricant to the powder.
The manufacturing process of Tungsten copper alloy is to press the refractory (tungsten or tungsten carbide), sinter the pressed compact at a high temperature, and infiltrate with copper. All of this is done under very closely controlled conditions. The mechanical and physical properties of tungsten copper alloy vary with composition. The thermal and electrical conductivity increase with the amount of copper, while the hardness, strength, and resistance to mechanical wear increase with the amount of tungsten or tungsten carbide. The application determines the material choice.

Tungsten Copper Alloy


Tungsten copper (copper tungsten, CuW, or WCu) alloy is pseudo-alloy of tungsten and copper. As copper and tungsten are not mutually soluble, the material is composed of distinct particles of one metal dispersed in a matrix of the other one. The microstructure is therefore rather a metal matrix composite than a true alloy.
Copper tungsten alloy is the composite of tungsten and copper, which own the excellent performances of tungsten and copper, such as heat-resistant, ablate-resistant, high-intensity, excellent thermal and electrical conductivity. Tungsten copper alloy is easy to be machined. Tungsten copper alloy is used widely in such industries as engine, electrical power, electron, metallurgy, spaceflight and aviation. Using CIP formation, sintered tungsten skeleton and infiltrating copper (silver) technology, large size and special shape products of tungsten copper composites with 6-90 percent of copper are produced, such as electric contacts, electrode, refractory parts, heat sinks and parts of rocket, We can also produce tungsten copper alloy sheet material, tubing, plate and other small products by mould pressing, extrusion pressing and MIM.
Copper tungsten alloy combines the properties of both metals, resulting in a material that is heat-resistant, ablation-resistant, highly thermally and electrically conductive, and easy to machine.
Parts are made from the tungsten copper alloy by pressing the tungsten particles into a desired shape, sintering the compacted part, and then infiltrating with molten copper. Sheets, rods and bars of tungsten copper alloy are available as well.
Commonly used copper tungsten alloy contains 10 to 50 wt. % of copper, the remaining portion being substantially all tungsten. The typical properties of the alloy depend on its composition. The alloy with less wt. % of copper has higher density, higher hardness and higher resistivity. The typical density of CuW90 alloy, with 10% of copper, is 16.75g/cm3 and 11.85g/cm3 for CuW50 alloy. CuW90 has higher hardness and resistivity of 260 HB kgf/mm2 and 6.5 µΩ.cm than CuW50.