Chắc bác nhầm với động cơ phản lực nào ấy chứ?
Ngày xưa máy bay Mỹ rơi nhiều, mấy cái động cơ của chúng cũng dễ thấy. Những cánh turbin phía sau dù có bị cháy hay còn nguyên bên trong đều có ánh biếc nâu đỏ chứ chẳng trắng như nhôm hay duyra. Ở vị trí của chúng, nhiệt độ rất cao thì nhôm gì chịu được (nhất là lúc máy bay tăng lực, lửa không đỏ mà hơi tim tím)?
Jet Engine Components and Materials
1. Fan Blades (Ti Alloy)
The fan blades are the first set of blades at the front of the engine. Made from titanium alloys (Ti alloys), these blades are designed for high strength, low weight, and resistance to fatigue. They help draw air into the engine, providing the initial stage of compression and thrust.
2. Fan Casing
The fan casing encloses the fan blades, ensuring that airflow is controlled and directed efficiently. It protects the blades and confines the air entering the engine.
3. Fan Shaft (Fe-Based Alloy)
The fan shaft connects the fan to the low-pressure turbine at the rear of the engine. Made from iron-based alloys (Fe-based alloys), the shaft must be robust enough to handle high rotational speeds and mechanical stresses.
4. Intermediate and High-Pressure Compressor Casings
These casings house the compressor blades, which compress the incoming air before it enters the combustion chamber. The compression process significantly increases air pressure and temperature.
5. Compressor Discs and Blisks (Ni Alloy)
Compressor discs and blisks (blades integrated into disks) are crucial for increasing the air pressure within the engine. These parts are made from nickel alloys (Ni alloys), which offer excellent high-temperature strength and resistance to oxidation.
6. High-Pressure Turbine Disc (Ti/Ni Alloy)
Located after the combustion chamber, the high-pressure turbine disc extracts energy from the high-temperature exhaust gases. A combination of titanium and nickel alloys is used to ensure the part can endure extreme thermal conditions while maintaining strength.
7. Intermediate Pressure Turbine Discs (Ni/Ti Alloy)
These turbine discs operate at slightly lower pressures than the high-pressure turbine but still need to withstand very high temperatures. The combination of nickel and titanium alloys provides the necessary durability and heat resistance.
8. Low-Pressure Turbine Discs (Ni Alloy)
Positioned further back in the engine, the low-pressure turbine discs also utilize nickel alloys. These turbines drive the fan and low-pressure compressor, extracting energy from the exhaust gases to maintain engine rotation.
Đây là hình của 1 động cơ turbofan, nhiệt độ động cơ chưa bằng turbjet đâu, mà cánh quạt (propeler) chịu nhiệt độ thấp nhất cũng phải bằng hợp kim titan: