On October 16, the Long March 2 F Yao 13 carrier rocket carrying the Shenzhou 13 manned spacecraft ignited at the Jiuquan Satellite Launch Center in China and successfully docked with the Chinese Space Station.
Looking at the history of China's aerospace technology development, it is also the history of China's high-performance advanced materials.
With the technological breakthrough of China's high-performance advanced materials, Hay Think reveals the secrets of China's advanced materials and applications for aerospace engines:
High Performance Alloy
1. Aluminum alloy
Aluminum alloy has outstanding advantages such as high specific modulus and specific strength, good corrosion resistance, good processing performance, and low cost, so it is considered to be the most important role in the aerospace industry.
Main application locations: engine compartment, cabin structure, load-bearing wall panels, beams, instrument installation frames, fuel tanks, etc.
2. Titanium alloy
Compared with aluminum, magnesium, steel and other metal materials, titanium alloy has the advantages of high specific strength, good corrosion resistance, good fatigue resistance, thermal conductivity and low linear expansion coefficient, and can be used for a long time under 350~450℃ , Low temperature can be used to -196℃.
Main application locations: compressor blades, casings, engine compartments and heat insulation panels of aero engines.
3. Ultra-high-strength steel
Ultra-high-strength steel has high tensile strength and sufficient toughness, and has good weldability and formability.
Main application locations: aerospace engine housing, engine nozzles, bearings and transmission gears.
4. Magnesium alloy
Magnesium alloy is the lightest metal structural material, which has the characteristics of low density, high specific strength, strong earthquake resistance, and can withstand large impact loads.
Main application locations: aerospace engine casing, gear box, etc.
High Performance Composite Materials
The rapid development of aero-engines, especially the increasingly stringent temperature and weight requirements, can no longer meet the gradual improvement of traditional materials. Instead, it calls for materials science to open up a new system, that is, composite materials. According to the respective characteristics of composite materials, it can be used on different parts of the engine.
1. Carbon-carbon composite materials
C/C-based composite material, that is, carbon fiber reinforced carbon basic composite material, combines the refractory of carbon with the high strength and rigidity of carbon fiber to make it show non-brittle failure. Because of its light weight, high strength, superior thermal stability and excellent thermal conductivity, it is the most ideal high temperature resistant material today, especially in the high temperature environment of 1000-1300 ℃, its strength not only does not decrease, but has seen an increase. It is a new material with more high temperature resistance that has received the most attention in recent years. The most significant advantages are high temperature resistance (about 2200°C) and low density, which can greatly reduce the weight of the engine to increase the thrust-to-weight ratio.
Main application position: If carbon-carbon composite materials can solve the oxidation problem of the surface and interface at medium temperature, and can increase the densification speed during preparation, and reduce the cost, it is expected to have a large number of practical applications in aero engines.
At present, there have been some applications, such as the tail nozzle of the afterburner on the F119 engine in the United States, the nozzle and combustion chamber nozzle of the F100 engine, and some parts of the combustion chamber of the F120 verification engine have been made of C/C-based composite materials. The French M88-2 engine and the Phantom 2000 engine's afterburner fuel injection rods, heat shields, nozzles, etc. also use C/C-based composite materials.
2. Ceramic matrix composite materials
Due to the advantages of high temperature resistance and low density, the application of ceramic matrix composite materials (CMC) in aero-engines has shown a development trend from low temperature to high temperature, from cold end to hot end parts, and from stator to rotor.
CMC material has excellent properties such as high temperature resistance, low density, metal-like fracture behavior, insensitivity to cracks, and no catastrophic damage. It is expected to replace superalloys to meet the use of hot-end components in higher temperature environments, and is not only beneficial Significantly reduce weight, and can save or even eliminate the need for air-conditioning, thereby increasing the total pressure ratio, achieving a further increase in the operating temperature of 400-500℃ based on the temperature resistance of high-temperature alloys, and a weight reduction of 50% to 70% in the structure, making it an upgraded aircraft engine Key thermal structural materials.
Main application locations: short-term targets are exhaust nozzles, flame stabilizers, turbine shroud rings, etc.; medium-term targets are applied to low-pressure turbine blades, combustion chambers, inner cones, etc.; long-term targets are locked in high-pressure turbine blades, high-pressure compressors and Guide vanes and other applications.
3. Resin-based composite materials
Advanced resin-based composite materials are composite materials with high-performance fiber as the reinforcement and high-performance resin as the matrix. Compared with traditional steel and aluminum alloy structural materials, its density is about 1/5 of steel and 1/2 of aluminum alloy, and its specific strength and specific modulus are much higher than the latter two.
Main application locations: Aeroengine cold end components (fan casings, compressor blades, intake casings, etc.), engine nacelles, thrust reversers and other components are widely used.
4. Metal matrix composite materials
Metal matrix composite materials mainly refer to composite materials based on light metals such as Al and Mg. In aviation and aerospace, it is mainly used to replace the light but toxic beryllium. This type of material has excellent lateral performance, low consumption and excellent processability, has become the most commercially attractive material in many applications, and has been commercialized abroad.
Main application position: suitable for the middle temperature part of the engine.