In the Second World War, silicone oil had a great influence in the war. When Germany entered the former Soviet Union, it was in the harsh winter of a hundred years. The oil inside the machinery was frozen. The fascist German mechanized troops and all the tanks and armored equipment of the former Soviet combat troops could not be used. In the face of this harsh situation, scientists in the former Soviet Union found that a mixture of substances and oils can prevent freezing. This substance is the silicone oil we know today. It is said that it is precisely because of the silicone oil that the former Soviet Union gained great advantages and defeated the German fascists, making an important contribution to the world anti-fascist war.














Military installations and military equipment are often made of materials with excellent properties due to their particularity, and silicone oil is one of these excellent properties. Silicone oil is often used in military applications:






Instrument oil


The use of silicone oil as the instrument oil has the characteristics of long service life, good oxidation stability, low volatility and use in a wide temperature range. China has three series of silicone oil instrument oil products -60-120 °C, -60-150 °C and -60-200 °C, which are widely used in precision instrument bearings, various aviation timing instruments, micro motor bearings and various instruments. lubricating.














Specific liquid


In the automatic control system of modern aircraft, a large number of liquid floating gyros, float accelerators, magnetic compasses, sensors, etc. are used, most of which use liquid suspension to reduce bearing load and friction torque, and improve sensitivity, accuracy and stability. The liquids required to have specific viscosity and density, good viscosity temperature performance and low freezing point. Representative silicone oil special liquids are No. 4118 gyro oil, No. 4119 damping oil, No. 4120 sensor oil No. 4126 gyro instrument oil.






Hydraulic oil


The US Air Force divides hydraulic oil into six categories according to the operating temperature range of the hydraulic system. The third and fourth types of operating temperatures are -54-204 ° C and -54-288 ° C, respectively. Silicone oil and silicate are most likely to meet the two. The specification of oils. American products such as Oronite 8200, 8515, 70 and the like, based on hexa-(2-ethylbutoxy)disiloxane, meet the specifications of MIL-H-8446 synthetic hydraulic oil. US OS-45, OS-45-1, France's FH-4, FH-8, China's 4601, 4602 aviation hydraulic oil and other hydraulic oils are also such products, but the working temperature is -54-175 °C. Methyl chlorophenyl silicone oil is also used as a hydraulic oil for aircraft, such as F-50, DP-47, MS-6 in the United States, and BT-301 in the former Soviet Union.














Shock absorber


High-viscosity silicone oil can be used as a shock absorber for torsional vibration transmitted from crankshafts such as diesel engines, automobiles, tanks, etc. It can also be used as a pointer for instrumentation instruments in aircraft, automobiles, motorcycles, ships, and various industrial devices with severe vibrations. The liquid is placed to make the meter display the correct indication when it is shaken vigorously. It can also be used as a buffer tank, shock absorber and other dampers.






Methyl chlorophenyl silicone oil with a normal temperature of 300 mm 2 / s can be used as a shock absorber for a rotary vane type hydraulic shock absorber of a tank, and is used for a motion tube of a spacecraft transmission device. Methyl silicone oil and methyl phenyl silicone oil can be used as the working fluid of the liquid space of the spacecraft, the shock absorber of the spacecraft shock absorber, the shock absorber of the submarine launching missile and the liquid spring of the soft landing support of the spacecraft.






Vehicles, especially the shock absorbers of tanks, are increasingly using oil and gas suspension devices instead of leaf spring shock absorbers. The shock absorbers used must have excellent viscosity-temperature properties, low-temperature fluidity, shear stability and rubber adaptability. And the blend of silicone oil and mineral oil can fully meet this requirement by adding various additives.














Brake fluid


Silicone oil has good hydrophobicity, chemical inertness and electrical insulation and is suitable for automotive brake fluid. Silicone brake fluids are available in MIL-B-4617A, FMVSS NO116 DOT5, SAEJ1705 and China's GB10830 JG5. These brake fluids are used in some military vehicles, tanks, and mail trucks.














Compared with the alcohol ether type brake fluid, the silicone oil brake fluid has the following characteristics: the silicone oil has low hygroscopicity, and its boiling point and viscosity are hardly changed after moisture absorption; it has a good phase for all metal and non-metal materials of the brake system. Capacitive; does not cause electrochemical corrosion; the brake system is stable, even in the high temperature of -250 ° C and -40 ° C, in a dry heat or humid environment, safe operation.






Heat transfer oil


The lower viscosity silicone oil is a good heat transfer medium. Methyl silicone oil, methyl phenyl silicone oil and methyl phenyl ether based silicone oil can transfer heat in the range of 100-300 ° C, adding a small amount of thermal oxidation stabilizer, can also make The working temperature is higher. Methyl silicone oil and methylphenyl silicone oil having a viscosity of about 150 mm 2 /s (20 ° C) can be used as a heat transfer medium for the oil bath to measure the high temperature viscosity of the fluid, and the melting point of the substance can be measured instead of the sulfuric acid bath. Silicone oil is non-corrosive, non-discoloring, and can be kept clear and transparent for easy observation. As a heat transfer oil used in industry, silicone oil is used more and more widely. The ethyl silicone oil with a viscosity of 200 mm 2 /s (20 ° C) can be used as a heat transfer medium in the jacket of the enamel reactor, and is used continuously below 180 ° C. After two years, the viscosity and acid value are substantially unchanged. The medium phenyl content of the silicone oil is used as a heat transfer oil in a production unit operating underground. A tetraaryl silicate or an alkyl aryl silicate can be prepared by using a small amount of a heat-resistant aromatic compound or a quaternary amine anti-hydrolysis and antioxidant, and can be used as a heat transfer oil to 380 ° C. The heat transfer oil as a solar heating device is a methyl silicone oil with an additive, and has the characteristics of low vapor pressure, low temperature, no freezing, and high temperature non-volatility, and can work stably for a long time under the maximum temperature of the solar collector of 200 ° C or less.














Electrical insulating oil


Silicone oil is suitable for use as insulating cooling oil, buffer oil, transformer oil, insulation impregnating oil and heat dissipating oil. After the 1970s, silicone oil has made some breakthroughs as electrical oil. Silicone oil transformer oil can work above 175 °C for a long time, allowing the transformer to work with 115 °C temperature rise (generally mineral transformer oil is only 65 °C), thus reducing the size of the transformer, and safe and reliable operation, low flammability, even Combustion also produces silica and self-extinguishing, eliminating the firewall and fire protection required to use mineral transformer oil. Silicone oil can be used in small transformers in aerospace and radio; as a filler and dielectric fluid in semiconductor and silicon rectifier components, it can improve the reliability and stability of components and extend the service life of components. In particular, methyl cyanosilicone oil, with a dielectric constant of up to 40, is more suitable as a dielectric fluid for the electrical and electronic industry, especially for ultra-small capacitors.














The low viscosity methylphenyl silicone oil has been used as an insulating immersion liquid for large power capacitors with satisfactory results. Porcelain insulators on substations and transmission lines, coated with silicone oil or silicone grease with a viscosity of 3000-5000mm2/s at 25°C, can eliminate the effects of rain, moisture and dust, and operate safely for 4-5 years.






Low-viscosity methyl silicone oil, ethyl silicone oil, low phenyl methyl silicone oil can also be mixed with a certain proportion of insulating oil such as dodecylbenzene or carbon tetrachloride to make transformers, capacitors, rectifiers, electromagnetic switches, Flame-resistant insulating oil such as conveyor.






Silicone Rubber


The difference between silicone rubber made of silicone oil is that silicone rubber has a larger temperature working range, ordinary silicone rubber can work between -40 ° C and 180 ° C, and special silicone rubber can withstand 300 ° C high temperature, resistant - 70 ° C low temperature. In addition to high and low temperature resistance, silicone rubber is resistant to radiation, water, insulation and other properties. Silicone rubber is often used as a sealing strip in military equipment, and some parts that are resistant to high and low temperature radiation.