General Characteristics.

Copper combines high electrical and thermal conductivity, ductility and corrosion resistance. It has good casting qualities, it is easily cut and processed by pressure in hot and cold condition. It is indispensable in electrical engineering, radioelectronics and instrument making, it is widely used in mechanical engineering and other branches. Pure copper is not used as often. It is mainly made into alloys: brass, bronze and copper-nickel alloys.

Composition of copper grades GOST 859-66

Impurity content is given in thousandths of a percent

Production

During smelting, copper actively absorbs oxygen to form copper oxide, which reduces conductivity and ductility and can cause "hydrogen sickness". When subsequently heated in hydrogen, _Cu2 O forms cracks and bubbles that reduce strength and ductility, as hydrogen combines with oxygen at high temperature to form water vapor, which delaminates the metal. To protect copper from oxidation, it is melted either under a layer of charcoal, or in an inert gas atmosphere, or in a vacuum. If necessary, the liquid copper is deoxidized. One of the most convenient deoxidants is phosphorus (in an amount of 0.01-0.05% P). Molten copper should also be protected from saturation with sulfur, which degrade its mechanical properties.

Use

According to GOST 859-66 produced dozens of different grades of copper in the form of ingots forgings, sheets, strips, bands, rods, pipes, wire, cathodes, vayerbase, copper - a good material for shaped castings, it is widely used for corrosion-resistant coatings. Anodes of AMF copper (GOST 767-70) are used more often for electrolysis. Addition of phosphorus to this copper contributes to better dissolution of anodes during electrolysis.

Electric welding

Good thermal and electrical conductivity of copper makes it difficult to electric spot or roller welding. Thin copper parts can be welded with a tungsten or molybdenum electrode. Pre-tinning makes welding easier. If you have high-power transformers, it is better to weld butt-weld. Parts thicker than 2 mm can be welded by acetylene-oxygen welding, protecting them from oxidation and contamination. The best way to join copper is by brazing with hard and soft solders.

Cold working

Copper is easy to stamp, but we should not forget that in the annealed state it has a pronounced anisotropy of mechanical properties, leading to the formation of festoons when deep drawing. Therefore sheet (strip) copper should be prepared by special technology. Finishing cutting of soft copper is difficult because of its high viscosity. Tungsten (hard) copper should be used for cut parts.

Hydrogen sickness.

According to GOST 15 471-70 determined the susceptibility to "hydrogen sickness" by annealing copper plates (40 min. at 825-875 ° C) in hydrogen, followed by inspection and testing for bending. The bending strength of flat bars is regulated in GOST 14 019-68, and the tensile strength is regulated in GOST 11 701-66 and GOST 1497-73. The bending strength of wire regulates GOST 1579-63, and the tension - GOST 10 446-63.

Buy, price

Evek GmbH sells copper and copper alloys at the best price. It is formed taking into account London Non-Ferrous Metals Exchange rates and depends on the technological peculiarities of production without additional costs. All products have a quality certificate for compliance with the requirements of standards. With us you can buy in bulk a variety of products for large-scale production. A wide range of products, comprehensive advice of our managers, reasonable prices and timely delivery determine the face of our company. Find us easily on the Internet at evek.org. A flexible system of discounts is available for wholesale purchases.