5/21/2023 0 Comments Density of copper![]() CuW is less likely to erode in air when the concentration of copper is higher in the material. It is not a good contact for air since the surface will oxidize when exposed. CuW is usually a contact for vacuum, oil, and gas systems. Copper tungsten is a good choice for a vacuum contact due to its low cost, resistance to arc erosion, good conductivity, and resistance to mechanical wear and contact welding. ![]() When the contact is very fine grained (VFG), the electrical conductivity is much higher than a normal piece of copper tungsten. ĬuW can also be used as a contact material in a vacuum. Graphite can be added as lubricant to the powder. Other ductile metals can be used as a binder in place of copper as well. Tungsten powder based shaped charge liners are especially suitable for oil well completion. 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. Other materials for this applications are copper-molybdenum alloy, AlSiC, and Dymalloy.Ĭomposites with 70–90% of tungsten are used in liners of some specialty shaped charges. 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. The CuW75 composite, with 75% tungsten, is widely used in chip carriers, substrates, flanges, and frames for power semiconductor devices. WCu alloys are also used in electrodes for electrical discharge machining and electrochemical machining. As contact material, the composite is resistant to erosion by electric arc. Some of the applications are in electric resistance welding, as electrical contacts, and as heat sinks. Typical properties of commonly used copper tungsten compositions CompositionĬuW composites are used where the combination of high heat resistance, high electrical and thermal conductivity, and low thermal expansion are needed. CuW90 has higher hardness and resistivity of 260 HB kgf/mm 2 and 6.5 μΩ.cm than CuW50. The typical density of CuW90, with 10% of copper, is 16.75 g/cm 3 and 11.85 g/cm 3 for CuW50. The mixture with less wt.% of copper has higher density, higher hardness, and higher resistivity. The typical properties is dependent on its composition. Sheets, rods, and bars of the composite mixture are available as well.Ĭommonly used copper tungsten mixtures contains 10–50 wt.% of copper, the remaining portion being mostly tungsten. Parts are made from the CuW composite by pressing the tungsten particles into the desired shape, sintering the compacted part, then infiltrating with molten copper. The material 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. The microstructure is therefore rather a metal matrix composite instead of a true alloy. 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. For other uses, see CuW (disambiguation) and WCu (disambiguation).Ĭopper–tungsten ( tungsten–copper, CuW, or WCu) is a mixture of copper and tungsten.
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