Copper Copper, also known as copper has good electrical conductivity and thermal conductivity, excellent plasticity, easy hot and cold pressure processing, a large number for the manufacture of wires, cables, brushes, electric spark erosion of copper and other special requirements good electrical conductivity products.
Copper is the copper industry, its melting point is 1083 ℃, no allotropic transformation, the relative density of 8.9, five times as magnesium. About 15% heavier than ordinary steel. Having a red rose, after the oxide film formed on the surface purple, it is commonly referred to as copper. It contains a certain amount of oxygen is copper, which is also called oxygenated copper.
Named because copper was purple. It is not necessarily a pure copper, and sometimes a small amount of deoxygenated elements or other elements to improve the material and performance, it is also classified as a copper alloy. Chinese copper processing material components can be divided into: general copper (T1, T2, T3, T4), oxygen-free copper (TU1, TU2, and high-purity, vacuum oxygen-free copper), deoxidized copper (TUP, TUMn), add a small amount of alloy special copper elements (arsenic copper, tellurium copper, silver and copper) four categories. Copper electrical and thermal conductivity second only to silver, widely used to produce electric and thermal conductivity equipment. Copper in the atmosphere, water and certain non-oxidizing acid (hydrochloric acid, dilute sulfuric acid), alkali, salt solution and various organic acids (acetic acid, citric acid), there are good corrosion resistance, for the chemical industry. In addition, copper has good weldability, can be the cold, processed into a variety of thermoplastic semi-finished and finished products. 1970s, copper production exceeded the total production of other types of copper alloy.
Copper trace impurities have a serious impact on the electrical conductivity, thermal conductivity of copper. Wherein a significant reduction of titanium, phosphorus, iron, silicon, conductivity, and cadmium, zinc, etc. are little effect. Oxygen, sulfur, selenium, tellurium solubility in copper is very small, and the copper compound may be generated brittle, have little effect on the conductivity, but can reduce the processing of plastic. Heating at ordinary copper hydrogen or a reducing atmosphere of carbon monoxide, hydrogen or carbon monoxide easy and cuprous oxide grain boundary (the Cu2O), thus producing a high pressure steam or carbon dioxide, copper can rupture. This phenomenon is often referred to copper "hydrogen disease." Oxygen copper welding harmful. Bismuth or lead generation and low melting point eutectic copper, copper thermal embrittlement produce; and brittle when a thin film of bismuth was distributed at the grain boundaries, and copper to produce cold crisp. Phosphorus can significantly reduce the conductivity of copper, but the copper solution can improve mobility, improve weldability. The right amount of lead, tellurium, sulfur, etc. can improve machinability. Annealed copper sheet tensile strength at room temperature of 22 to 25 kgf / mm2 and an elongation of 45 to 50%, and Brinell hardness (HB) 35 to 45.
It has excellent electrical conductivity, thermal conductivity, ductility and corrosion resistance. Mainly used for flat plate collectors and other thermal equipment manufacture generators, bus, cable, switch gear, transformers and other electrical equipment and heat exchangers, piping, solar heating device. Commonly used copper alloy brass, bronze, copper-nickel alloy is divided into three categories.
Pure copper metal is purple, commonly known as "copper", "copper" or "Akagane."
Copper rich ductility. Like a drop of water the size of a copper, it can grow up to two kilometers to pull filaments, or rolled into a bed bigger than almost transparent foil. Copper is the most valuable properties of the conductive performance is very good, second only to silver in all of metal. However, silver is much cheaper than copper, so the electrical industry has become a "hero."
The use of copper is much broader than pure iron, each year 50% of electrolytic copper is purified as copper, for the electrical industry. Here, the copper is indeed to be very pure copper over 99.95% of the job. A very small amount of impurities, especially phosphorus, arsenic, aluminum, etc., will greatly reduce the conductivity of copper. Copper oxygenated (easily mixed with a small amount of oxygen when copper) on a large conductivity for electrical industry generally must be oxygen-free copper. In addition, lead, antimony, bismuth and other impurities cause copper crystals can not be combined together, resulting in hot brittle, it will also affect copper processing. This high purity copper, general electrolysis refining: the non-copper (ie blister) as the anode, copper as the cathode, with copper sulfate solution as electrolyte. When the current passes through the impure copper anode gradually melting copper will gradually precipitate on the cathode. Such refining of copper; purity of 99.99%.