Other insulating materials

High-performance insulation material that has been following the spacecraft into space ------ Fluorite mica flakes

The fluorite crystal mica texture is very pure, and it does not contain OH-(hydroxyl). Its chemical formula is KMg3(AlSi3O10)F2(OH)-. Fluorine replaces the hydroxyl group. Electrical performance is also very good. The volume resistivity is 1015~1016Ω•cm (approximately 1000 times higher than that of natural mica); the electric breakdown strength is 185~238kv/mm, which is 10 times that of PTFE; and the safe use temperature can reach 1100°C. . Its melting and crystallization temperature is 1375°C.

The fluorocrystal mica has a very good thermal shock stability. The five labs of Saibao Laboratories, Guangzhou, Ministry of Information Industry, conducted 10 cycle tests at -40°C to 70°C, all of which were qualified.

Natural mica is an underground natural ore that contains many impurities and contains OH-(hydroxyl). Its ideal chemical formula is KAI2(AISi3O10)(OH)2 and KMg3(AISi3O10)(OH)2, with unstable electrical properties. The electrical properties at high temperature and high frequency are even worse. When the temperature is above 500°C, the characteristics of mica are gradually lost due to dehydration. The commonly used insulating material PTFE, because of its poor temperature resistance, can only be used in low temperature environments, and its production is easy to have metal impurities, corona is not good. It can be seen that the electrical insulating properties of natural mica and PTFE are incomparable with that of fluorite mica. .

Fluorocrystalline mica has been selected by CEC Shijiazhuang No. 13 for national key aerospace projects - Shenzhou No. 8, No. 9, No. 10 ... spacecraft and various satellites as insulating spacers. Nine schools in Mianyang were also selected as electrical insulation materials. Fluorocrystalline mica is an ideal electrical insulation material for high-end technology.

Insulating materials commonly used in the general industry are natural mica and polytetrafluoroethylene. Natural mica is an underground ore naturally formed and belongs to silicates. Its ideal chemical formula is KAl2(AlSi3O10)(OH)2 and KMg3(AlSi3O10)(OH)2, containing (OH) deuterium (hydroxy). Due to the presence of hydroxyl (water molecules), its performance in all aspects is far lower than that of fluorophlogopite. Natural mica contains a lot of impurities, the electrical properties are unstable, and the electrical properties at high temperature and high frequency are even worse. When the temperature is above 500 DEG C, the characteristics of mica are gradually lost due to dehydration.

    PTFE, because of its poor temperature resistance, can only be used in low temperature environments (generally not more than 300 °C), and its production is easy to have metal impurities, corona is not good.

It can be seen that the electrical insulating properties of natural mica and PTFE are incomparable with that of fluorite mica.

        Fluorocrystalline mica is an ideal electrical insulation material for high-end technology. It has been nearly 10 years since 2005 when it was selected for the aerospace equipment as an insulation gasket by the 13th research group of Shijiazhuang of the China Power Group. In the past ten years, the 13th Institute has applied fluorocrystal mica to all space equipment including the spacecraft No.8, No.9 and No.10 of China, and environmental monitoring satellites (pointer No.9) as insulating films.