2015年8月26日星期三

Copper tungsten alloy is what color

copper tungsten materials of tungsten-copper alloy exhibits most of the orange, but according to the proportion of tungsten copper, the color can change. If the content of copper as many colors tend to be the color of copper, tungsten, if the proportion tends to tungsten color, the silver-white.
Tungsten copper alloy in high-voltage switchgear 128kV SF6 circuit breakers WCu / CuCr in, as well as high-voltage vacuum load switch (12kV 40.5KV 1000A), surge arresters are widely used, high-voltage vacuum switch, small size, easy maintenance, using a wide range of energy in the wet, use flammable and corrosive environments. The main performance requirement is resistance to arc erosion, anti-welding, off current is small, less gas, low thermal electron emission ability. In addition to conventional macro performance requirements, but also requires the porosity, microstructure properties, it should take a special process, the need to vacuum degassing, vacuum infiltration and other complex processes.
Early EDM electrode made of copper or graphite electrodes, inexpensive but impatience ablation, has been largely replace tungsten copper electrode. Advantages of tungsten copper electrode is high temperature, high temperature strength, resistance to arc ablation, and thermal conductivity good performance, fast heat dissipation. Applications concentrated in EDM electrodes, welding electrode and high voltage discharge electrodes.
EDM electrode is characterized by many different specifications, the total volume is small and more. As EDM Electrode tungsten copper material should have as high a uniformity of density and organizations, in particular the elongated rod, tubular and shaped electrodes.
W-Ni- Fe alloy is composed of W, Ni, Fe powder is mixed pressing sintering. Wherein the amount of tungsten up to 80% to 90% and nickel, iron acts as bonding agent. After a two-phase alloy liquid phase sintering, density and theoretical density similar. Nickel is a liquid phase sintering process essential element, generally an amount of 0.5% to 12%, if more than 12%, the heat resistance of the alloy and the corrosion resistance are lowered. Iron content is generally between 0.5% to 8%, if more than 8% of the brittleness of the alloy increases. Iron in the alloy can improve the strength and ductility of these alloys have a certain magnetic core material can be used as armor-piercing bombs, cluster bombs, high anti-fragment momentum, the counterweight and other industrial fields. Compared with the W-Ni-Cu alloy strength and ductility of the alloy are better.

2015年8月23日星期日

Copper tungsten alloy made whole cylindrical shaft protection sleeve called bushings

Equivalent bush bearing outer ring, the sleeve is integral, and relative to the shaft is in motion, while bearing some fragmentation, relative to the shaft is rotated.
Bush in LEGO Mindstorms series and BioTrans RoSys series robot assembly especially silver Lego standard shaft holder, sub full sleeve 1/2 sleeve two.
Various types of bushings on the major water conservancy generator set, the main material ZQAl9-4, ZQSn10-1, ZQSn6-6-3.
Made whole cylindrical shaft protection sleeve bearing sleeve called the equivalent bearing outer ring, sleeve is integral and is stationary relative to the shaft, and bearing some fragmentation, relative to the shaft is rotated ʱ??
Bearing assembly advised before cleaning with kerosene or diesel clean, dry and oil immersed in oil. Bearing and seat hole assembly, it is necessary to keep the bearing seat hole rotation and axial movement does not occur, to make full contact with the outer surface of the bearing seat hole, the general should ensure that the contact area is greater than 70% or more, in order to facilitate the receiving surface is Machined Copper Tungsten Parts back , steel-on-steel friction coefficient than Copper Tungsten alloy Part large coefficient of friction of plastic, so use with relatively lightweight, both to ensure the use of the seat cover does not move relative to the hole, and not leave the bush so that the outer diameter is too large bush hole large deformation.
Injured equipment likely to cause wear bushings run, resulting in low productivity, accelerated aging equipment, the impact of product quality and a series of hazards, severe cases can cause the device to be forced to shut down or stop the entire production line, resulting in loss of production time, the delay in the delivery shipment dates or even cause serious production safety accidents, equipment due to individual industries bushings wear, production downtime and even forced through the entire production line of all scrapped accidents, resulting in companies forced into bankruptcy overnight.

2015年8月20日星期四

Copper Tungsten Alloy presentation

Copper tungsten alloy powder metallurgy method of preparation of tungsten-copper alloy for the milling process - mixing the ingredients - pressing - sintering dissolved seepage - cold.
Tungsten, copper or molybdenum copper mixed powder after pressing, the liquid phase sintering at 1300-1500 °. Preparation of this legal material is uniformly bad, there are more closed the gap, the density is usually less than 98%, but by adding a small amount of nickel activated sintering method, a mechanical alloying method or an oxide reduction method for ultra-fine, nano-powder can improve the sintering activity, thereby increasing tungsten, Copper Tungsten Electrical Contacts, molybdenum density copper alloy. However, electrical conductivity, thermal conductivity of nickel activated sintering material will significantly reduce the mechanical alloying also reduce the introduction of impurities in the material conductivity; oxide powder prepared by co-reduction, process cumbersome, low productivity, difficult to mass production.
Injection molding
Injection-molded high-density tungsten alloy become. Its manufacturing method is uniform particle size of 1-5 microns nickel powder, copper powder or iron and tungsten particle size of 0.5 micron tungsten powder and tungsten powder mixing 5 to 15 microns, and then entering into the 25% -30 % organic bonding agents (such as paraffin or polymethyl methacrylate vinegar) injection molding, using steam cleaning and irradiation in addition to the binder, sintering in hydrogen, to obtain high-density tungsten alloy.
Copper oxide method
Copper oxide (mixing and grinding restore to Copper tungsten material) instead of metal copper, copper continuous matrix is formed in the sintered compacts, tungsten as strengthening the framework. Subject to the high expansion component around the second component, powder sintering at a lower temperature wet hydrogen. According to reports, the use of a very fine powder can improve the sintering properties and densification to reach more than 99%.
Tungsten, molybdenum skeleton Infiltration
First tungsten powder or molybdenum powder pressing and sintering tungsten, molybdenum skeleton has a porosity and infiltration copper. This method is suitable for low copper content tungsten copper, molybdenum copper products. Compared with tungsten, copper molybdenum copper, with a small mass, easily processed, linear expansion coefficient, thermal conductivity and mechanical properties of some of the major copper and tungsten considerable advantages.
It is the use of high-purity tungsten copper tungsten metal powder excellent characteristics and high purity copper powder plasticity, high electrical conductivity, etc., through the static pressure molding, high temperature sintering, melting refined copper infiltration process of composite materials. Breaking arc performance, good thermal conductivity, low thermal expansion, high temperature does not soften, high strength, high density, high hardness.

2015年8月17日星期一

Copper tungsten alloy tungsten copper composites

copper tungsten machining alloy tungsten copper composites: deflection tester to measure the shaft and sleeve-type parts of the disc runout, with a pair of Mohs hardness 4 # top, the progress of the new deflection tester's measurement accuracy, increasing Part of the measured radial support weight, high-precision measurement of parts, face and oblique runout. Yaw check the meter frame compact design fair, from top to bottom, front, left freely adjust smooth, convenient manipulation, table frame rigidity, improve the detection equipment agility. General deflection tester should fit a small cast iron platform.
Resin sand stiffness, high initial strength which pouring sand conditional use graphite cast iron solidification process of expansion, effectively eliminate shrinkage, shrinkage defects, to achieve gray iron, ductile iron and less riser, non-riser casting. And other large machine bed casting mold has a great advantage compared to traditional sand, it not only eliminates the need for expensive wood type costs, and ease of operation, shortening the production cycle, improve production efficiency importance of the development of tungsten-copper composite material
W-Ni-Cu alloy is mainly composed of W, Ni, Cu powder is mixed pressing sintering. Wherein, W content is generally 80% to 90% Ni and Cu binder was added after the two-phase alloy liquid phase sintering, a density close to the theoretical density. The alloy, in addition to W, Ni content is outside the residual copper content. Copper in the alloy can improve the strength and ductility of tungsten alloys. In terms of performance, the alloy special applications do not magnetic, and other physical properties of tungsten alloy having the same overall performance.
Machined Copper Tungsten Parts composite material made of high melting point, tungsten, high-density and high conductivity and low thermal expansion coefficient and high thermal conductivity of copper composition, combines both superior performance, such as having a high thermal conductivity, low coefficient of expansion, excellent high temperature strength and Anti-arc erosion properties. Back in the 1930s tungsten-copper composite material because of its good compressive strength and resistance to electrical ablation performance, high-voltage electrical switches and other industrial sectors has been widely used. Into the sixties, tungsten-copper composite material gradually gained in the field of welding electrode applications, aerospace components and other high temperature. Since then, with the gradual increase preparation technology, in the nineties as electronic packaging and heat sink material starts in the field of LSI and high-power electronic devices such as access to a wide range of applications. The twenty-first century, the tungsten-copper composite material is used as cover material HEAT medicine, materials and target missile nozzle caused concern in the military and high-tech fields.
Now, tungsten-copper composite material because of its good electrical conductivity, thermal conductivity and excellent thermal stability, has become a high-power microwave devices and ultra large scale integrated circuit substrate, slug, essential key material connections and cooling components, etc. its high thermal conductivity, high thermal stability and good near-net shape forming, can increase the use of power microelectronic devices, it is conducive to miniaturization of devices and sophisticated development. Low thermal expansion coefficient and the thermal expansion coefficient of tungsten-copper composite material adjustability, enabling semiconductor materials and microelectronics devices connected to its match in silicon, gallium arsenide and other useful ceramic materials, to avoid thermal fatigue damage caused by thermal stress broaden the tungsten-copper composite material in the field of microelectronics applications. Rate with high dimensional accuracy, small allowance, good surface quality and other advantages.

2015年8月6日星期四

Copper Tungsten alloy Part

Tungsten copper alloy combines the advantages of tungsten and copper, wherein the high melting point of tungsten (tungsten melting point 3410 ℃, melting point of copper 1080 ℃), density (tungsten density 19.34g / cm3, the density of copper 8.89 g / cm3) ; excellent thermal conductivity properties of copper, tungsten copper alloy (composition generally ranges WCu7 ~ WCu50) uniform microstructure, high temperature, high strength, resistance to arc erosion, high density; moderate conductivity, thermal conductivity, high-temperature materials are widely used in military , high pressure switch with electrical alloy, EDM electrode, microelectronic materials, parts and components as widely used in aerospace, aviation, electronics, electricity, metallurgy, machinery, sports equipment and other industries.

2015年8月3日星期一

WCu Electrode material

Early EDM electrode made of copper or graphite electrodes, inexpensive but impatience ablation. Advantages of tungsten copper electrode is high temperature, high temperature strength, resistance to arc erosion, thermal conductivity and good performance, fast heat dissipation. Applications focused on EDM electrodes, welding electrode and high voltage discharge electrodes. EDM electrode is characterized by many different specifications, but the total amount of more than small quantities. As EDM Electrode tungsten copper material should have as high a uniformity of density and organizations, in particular the elongated rod, tubular and shaped electrodes.