Materials used in electrical engineering.
Electrotechnical products are manufactured from a wide variety of materials, which, due to their performance properties, have been divided into the following groups: conductive materials, Design, electrical insulation, Magnetic, chemical and auxiliary.
Conductive materials include metals, and in particular: silver (Ag), copper (With) and aluminium (Al). They are above all very good conductors of electricity, however, you should pay attention to this, that they gradually lose these properties as the temperature rises.
The best conduction properties are characterized by silver, precious metal of light grey colour, malleable, resistant to weather conditions, and especially oxygen.
Copper is minimally a worse conductor than silver, has a red color. Under the influence of oxygen, it oxidizes, forming a thin layer of patina and is no longer destroyed.
Aluminium is a very light metal, increasingly displaces copper in the electrotechnical industry. In the air it is covered with alumina, which at the same time provides protection and protects against further destruction of the metal.
Among the construction materials should be mentioned: stood, cast iron, copper alloys with cadmium.
Steel - Iron Alloy (Fe) with coal (C), silicon (And) and a small amount of other elements, obtained from blast furnace pig iron. Has good electrical and mechanical properties.
Blast furnace pig iron is also used to obtain cast iron — an alloy of iron and carbon, admixture of silicon (And), manganese (Mn) and phosphorus (P). A Copper alloy (With) with cadmium (Cd) has good electrical properties, mechanical, high resistance to oxygen. This alloy has much better technological properties, i.e.. easier to work than metals, which are constituents of this alloy.
Electrical insulating materials are used to separate two or more conductive elements from each other. They can create an insulating barrier between the conductive elements, and metal parts of the equipment. They also provide protection against electric shock during the use of electrotechnical products. As electrical insulating materials are used: rubber, thermoplastics, paper, fibrous yarns, ceramics.
Gum, marked in electricity with the symbol G, depending on the utility needs, it is obtained from natural rubber, synthetic and volcanic agents. As a good dielectric, it also has good mechanical and technological properties. The main disadvantage of rubber is the relatively fast aging process, the symptom of which is deterioration of mechanical properties.
Paper, used in electronics, is obtained from crushed pine or spruce wood, and then saturated with special insulating substances. The low cost of paper production contributed to its widespread use. A Electrotechnical ceramics are characterized by a low coefficient of thermal expansion. It is resistant to high temperatures and chemicals. Individual elements or entire ceramic units can be given a perfectly smooth surface, which is a valuable advantage of this electro-insulating material.
A commonly used plastic in electrical engineering is, among others. polwinit, that is, softened polyvinyl chloride (symbol Y) and polyethylene (symbol X). Addition of other substances, similar to rubber, improves the desired properties, for example. flexibility can be increased, resistance to low temperatures, dielectric properties, Winding-up susceptibility.
Magnetic materials include steels with good magnetic properties. They are used for the production of generator sheets, transformers and the production of magnets for electric meters and other measuring devices.
Chemical materials are well-known electrolytes, that is, water solutions of chemical compounds, especially sulfuric acid(WE) — H2SO4, which is in the batteries.
The auxiliary materials include varnishes, colors, emalie, which serve as film-forming substances for coating electrical engineering products. They are also often protective and anti-corrosion coatings.