Mica is one of the materials used in electrical engineering and can be found in many electric motors, generators and transformers. Especially in areas of heavy use: high pressure and high temperature.
Ⅰ. What is mica?
Mica is named for its shimmering appearance. Different types of mica can be easily distinguished by colour. Muscovite has a light appearance and phlogopite has a dark appearance. Mica is a mined mineral. It belongs to the monoclinic crystal system and consists of basic aluminium silicates of different compositions.
From the large number of natural mica types, only two technical requirements are questioned: muscovite and phlogopite.
Muscovite, also known as potassium mica, is a potassium aluminium disilicate. Muscovite is available in a variety of colors: ruby in colour, but also in white, green or brown.
Phlogopite, also known as magnesia mica, is a potassium-magnesium-aluminum-iron disilicate. Phlogopite has only one color in nature: the colour is similar to that of amber, so it is also called amber mica.
Ⅱ. The history of mica
Mica was mentioned as early as 1546 by the mineralogist Georgius Agricola. Where mica is readily available and affordable, and glass is too expensive, the mineral is used to make window panes, especially in rural areas.
In the 20th and 19th centuries, Charles-Victor Mauguin used X-rays to study mica for the first time. Mica means faint glow or glow.
Mica can be found almost anywhere in the world, but is worth mining in India, South Africa, Latin America and Russia, where it is embedded in bedrock in lumps or slabs.
Ⅲ. Performance and technical data of mica
1. Physical properties of mica products
Mica has very good electrical insulation and good thermal conductivity. And creep and dielectric strength are also very good.
2. Mechanical properties of mica
Mica is a silicate, a compound of silicon. Mica always has a two-dimensional layer structure. Strong bonds work within layers, but weaker bonds between layers.
Ⅳ. What is use of mica?
Due to the above properties, mica sheet is an ideal insulator for mounting power transistors on cooling plates. Due to its heat resistance, it is also used as an insulator holder for heating elements.
The HF value is also noticeable, which is why it is used as a dielectric for high-quality high-frequency capacitors. Various components are used in the insulation system of high-voltage motors, which must be optimally matched to each other. High-quality mica products (mica tape and mica plate) are used as main and partial conductor insulation.
The main uses of mica components are:
Construction of induction furnaces, electric arc furnaces and high frequency furnaces;
High pressure applications;
High temperature applications;
Sealing industries (e.g. oil and gas distribution);
Heating elements for electrical and thermomechanical applications.