Copper is a mineral that has been present in human life for many millennia. In ancient times, it was used mainly to obtain bronze in an alloy with tin. In Latin, its name is Cuprum. It was given to him by the ancient island of Cyprus, which was one of the first places where copper was mined and smelted from mines.
Historical background, characteristic of copper
Copper belongs to the order of basic chemical elements. In its natural (pure) form, it is a metal with a red-orange tint. It is used for the manufacture of a very large number of products, which include electrical wires, dishes, pipes, car radiators, etc.
Information from archaeologists suggests that copper began to be used more than ten thousand years ago. So a copper pendant, discovered in the northern regions of modern Iraq, was made around 8700 BC.
Copper has high thermal and electrical conductivity, is easily processed both hot and cold. She has a very high corrosion resistance. This is due to the fact that copper creates a very thin oxide protective layer on its surface as a result of its reaction with oxygen.
Copper is widely used in the production of acoustic, electrical and other wires, being present there as a metal of high purity or with small additions of silver, arsenic, phosphorus, tellurium, and sulfur.
Receipt process
Highly purified oxygen-free copper is obtained in the process of so-called electrical refining. It settles on the cathodes of electric cells, as a result of which it has another name - cathode copper. Purity reaches about 99.99%. Such a metal is also called oxygen-free copper, which has a high degree of purification (OFC - Oxygen-Free Copper).
The molten pure copper is subsequently poured into special forms that have square or rectangular sections. This process takes place in a vacuum, in the absence of oxygen, which prevents its penetration into the molten metal. The absence of oxygen impurities in such copper significantly increases its conductivity and strength.
Purity
OFC oxygen-free copper has various degrees of purification. The purity of the metal is indicated as follows: "* N". At the place of the asterisk (*), insert a number that discloses information about the number of nines after the decimal point. So, the oxygen-free copper grade OFC 6N reports that the pure metal in it is 99.999999%. The amount of impurities is 0.000001%.
The first production of 6N quality copper was carried out in 1985 in Japan by Nippon Mining Co. Highly purified oxygen-free copper went into mass production in 1987. The main areas of application then became acoustic wires, interconnect network cables.
Currently, such pure copper is produced by quite a lot of manufacturers in the world, including in the Russian Federation.
Some companies claim that they have achieved a degree of purification higher than 6 -7N, 8N, etc. But it should be borne in mind that at present there is no unity in determining the standards of purity of oxygen-free copper and its quality. In some cases, the presence of any impurities is simply not taken into account. Typically, such foreign inclusions include silver.
Advantages of metal
The advantages of oxygen-free OFC copper include the following:
- in a vacuum, when heated, it does not break and does not become brittle;
- able to easily change shapes during cold deformation (when exposed to pressure in conditions of room or close to them temperatures);
- when in various conditions does not change its color;
- the average electrical resistance of such a metal is constant;
- conductivity is always high;
- this metal is homogeneous in its structure;
- freely processed by high temperature soldering and welding.
Areas of use
Due to its qualities and properties, oxygen-free copper has found application in a variety of products, namely:
- transformer windings are made from it;
- used in the production of coaxial cables;
- used in electronic systems and devices;
- irreplaceable metal in superconductors and linear accelerators;
- it is an important structural element of telecommunication wires and cables intended for operation under water;
- It is part of the current transformer wiring.
Oxygen-free copper is also used in vacuum technology. It is indispensable in the design of vacuum distribution systems and semiconductors.
It is widely used in the manufacture of products for the space industry.
Among other areas where oxygen-free copper is used, there are: electronics, microelectronics, radio and instrument making, nuclear energy, jewelry and the construction industry.
From it make wires and pipes designed to work in strong electromagnetic fields. Oxygen-free copper is the basis for the manufacture of electrochemical anodes.
Copper Cathode Cables: Application
Modern cable products made using oxygen-free copper are highly conductive. This makes it possible to carry out high throughput of electrical signals with smaller wire cross sections.
However, it is worth noting that oxygen-free copper cables were not widely used. And all because the wires of this metal are of high cost. To achieve the desired parameters, they use simple copper with a large diameter, preferring not to splurge on expensive items made of oxygen-free copper.
But there are areas in which high conductivity is preferred in combination with a small wire diameter. This is necessary to ensure, including an aesthetic appearance. Such areas include the production of musical equipment, high-quality headphones, as well as those where you need to get devices that reproduce high-quality sounds of a professional level.
When using such copper, its advantages in resisting internal corrosion are noted. Due to this property, oxygen-free copper wires do not lose their characteristics over time. For this reason, cables filled with this metal are used in environments where high humidity is present.