Differences in Fluorophlogopite and Natural Mica and Polytetrafluoroethylene
1. Electrical performance:
Due to the purity of texture, Fluorophlogopite has high bulk resistivity (about 1000 times higher than natural mica), and the safe use temperature can reach 1100℃. The electrical breakdown strength of fluoro-crystalline mica decreases with the increase of mica sheet thickness. Natural mica contains a lot of impurities, and its electrical properties are unstable, and its electrical properties are worse at high temperature and high frequency. When the temperature is above 500℃, it will gradually lose its mica properties due to dehydration.
Polytetrafluoroethylene also has good electrical insulation performance, but because of the easy existence of metal impurities in the production of polytetrafluoroethylene, thus affecting the electrical performance. The corona resistance of polytetrafluoroethylene is not good, so it can not be used as a high voltage insulation material, which is incomparable with the fluorite mica.
2. Vacuum venting performance:
The vacuum gas discharge of fluoro-crystalline mica is low, and the trace gases emitted by mass spectrometer are only adsorbed gases such as O2, N2 and Ar. Because it does not release H2O vapor, it is extremely valuable for using as electric vacuum insulation material, which can greatly improve the service life of vacuum devices.
Natural mica will decompose H2O and other volatile components at high temperature, so the vacuum air discharge is high. At about 900℃, it is 2000 times higher than fluorite mica.
The structure of polytetrafluoroethylene is compact and has certain vacuum properties. It has very low permeability, low vapor pressure and low exhaust rate at room temperature, but is limited by the temperature of use, and is not easy to use in high temperature or temperature unstable environment.
Vacuum emission curve of fluorophrystalline mica at high temperature
3, physical performance:
Fluorocrystalline mica is not easy to deform, can withstand large pressure, and has high tensile strength and compressive strength. Teflon tends to flow and even break at high loads. When the loading is higher than 3MPa, residual deformation will occur, and when the loading is about 20MPa, it will be crushed. Ptfe has poor wear resistance, easy to deform under long-term stress, tensile strength, bending strength, impact strength, rigidity, hardness, creep resistance, fatigue resistance and other properties are poor.