It is mainly used for hot end parts, accounting for more than 40% by weight. Superalloys usually refer to alloy materials that can resist oxidation, corrosion and creep at high temperatures of 600-1200 ℃, and can work for a long time under high mechanical stress. Since the first furnace of superalloy GH3030 was successfully tested in 1956, the research, production and application of superalloys in China have experienced more than 60 years of development.
The technical progress of aeroengine is closely related to the development of superalloy. Superalloy is the most key structural material to promote the development of aeroengine. In the new advanced aeroengine, the amount of Superalloy accounts for more than 40% – 60% of the total weight of the engine. It is mainly used for the four hot end components of combustion chamber, guide, turbine blade and turbine disk. In addition, it is also used for gearbox, ring, afterburner and tail nozzle.
2. Titanium alloy
With high thermal strength and specific strength, it is widely used in fans and compressor discs. Titanium alloy refers to the alloy metal made of titanium and other metals. It has the characteristics of high strength, low density, good corrosion resistance and high heat resistance. It can still work stably for a long time in the environment of 450-500 ℃. At the same time, it can reduce the structural weight, improve the structural efficiency and help the engine have a higher thrust weight ratio.
Titanium alloy is the main structural material of aircraft and engine. It is mainly used for engine fan disc, compressor disc, fan blade, landing gear, fuselage beam, etc. since the 1960s, the amount of titanium used in aircraft has increased year by year. According to the disclosure of the Western superconducting prospectus, at present, the amount of titanium alloy in European and American advanced military aircraft has exceeded 20%, of which the amount of titanium in F-22 Raptor aircraft accounts for 41%.
3. New composite materials
It can withstand high temperature and low density. Compared with superalloys, ceramic matrix composites (CMC) have lower density, which is only 1 / 3-1 / 4 of that of superalloys. At the same time, the normal working temperature of CMC can reach more than 1200 ℃, and the potential service temperature can reach 1600 ℃. The higher tolerable temperature makes CMC only need less gas for cooling, put more air into the combustion chamber for combustion, and obtain greater power. CMC has gradually become an ideal material for hot end components such as aeroengine combustion chamber and turbine.
Common materials for aircraft accessories