In the aviation industry, silicone resins are mainly used as high temperature resistant coatings. For example, silicone high-temperature insulation coatings can withstand long-term heat resistance of 600°C and short-term resistance to 700°C. They have excellent electrical insulation properties, high adhesion, and high and low temperature resistance. They are used in engine cables, windings, hot rollers and electric heating equipment. The high temperature resistant and laser ablation resistant silicone coating is coated on the steel. The 900μm thick coating is exposed to 531 W/cm2 laser power density for 4s. The temperature of the coated steel substrate is lower than that of the blank steel substrate by about 1,000°C. Laser thermal protection applied to sensitive parts of aircraft. Low-temperature curing heat-resistant silicone resin-based coatings, long-term heat-resistant to 300 ℃, with good heat resistance, adhesion and good media resistance. It is used on the inner and outer surfaces of engine low-pressure turbine shafts and fan shafts. High temperature resistant infrared stealth coating has excellent heat resistance, good adhesion and high temperature infrared wave stealth performance below 300 ℃. It is used in engine infrared stealth and near the engine tail nozzle.
Silicone resins and modified silicone resins are important components of high-temperature adhesives. Russia has conducted in-depth and systematic research in this field, and has developed a number of modified silicone resin adhesives for use in the aviation field. For example, silicone phenol formaldehyde resin adhesive has long-term temperature resistance of 450-550℃, short-term resistance of 1000℃, and has excellent water resistance, fuel resistance and lubricating oil resistance. It is used to bond metal and non-metal materials (such as graphite, glass cloth composite materials and Heat protection material). The high-temperature resistant silicone resin adhesive is long-term resistant to 700°C and short-term resistant to 1200°C. It is used to bond titanium alloys and heat-resistant non-metallic materials (glass cloth composite materials and heat-resistant materials) in structural parts.
Silicone resin is not used as a high temperature sealant, but it is very important. It is an important solution for some harsh sealing environments. For example, the long-term working temperature of components such as air-to-air heat exchangers and pneumatic actuators of aircraft engines reaches 500℃. The HM 310 silicone resin sealant used in the heat-resistant 500℃×36h will not be skinned or not. Bubbling, no cracking, no falling off, adhesion reaches level 1, no air leakage after 1.0 MPa pressure test, and good high temperature resistance sealing performance. The working temperature of the combustion chamber of the aircraft engine or gas turbine and the rectifier installation side and adjusting ring can reach 800℃. The HM 311 heat-resistant silicone sealant used is treated at 800℃×36h, and it does not leak after the 2.5MPa pressure test. .