Aeroengine blades are one of the core components of aerospace engines, and its manufacturing workload accounts for more than 1/3 of the entire engine manufacturing. With the development of society, the requirements for lightweight of aerospace engines are getting higher and higher. Scientists are constantly looking for breakthroughs in blade materials and technology. Today, let's take a look at what are the materials for aerospace engine blades:
Aeroengine blade material classification
A. Deformed high temperature alloy
The development of wrought superalloys has a history of more than 50 years. The main types of wrought superalloys commonly used in domestic aircraft engines are Cr-Ni alloy system and Cr-Ni-Co alloy system. Refer to Table 1 for details. With the increase of aluminum, titanium, tungsten, and molybdenum content, the material properties of high-temperature alloys continue to improve, but the hot workability decreases; after adding the expensive alloying element cobalt, the overall performance of the material and the stability of the high-temperature structure can be improved.
B. Casting superalloy
The stability of the cast turbine blades increased from about 750°C in the 1940s to about 1700°C in the 1990s. The cast superalloys for blades are shown in Table 2.
C. Superplastic forming titanium alloy
At present, the most commonly used titanium alloys for superplastic forming blades are Ti6Al4V and Ti6Al2Sn4Zr2Mo. For more titanium alloy materials, see Table 3. Although the application of composite materials has recently increased, it has shortcomings that are difficult to solve at this stage, such as high manufacturing costs. , Can not be recycled, high temperature performance is poor, so titanium alloy is still the main material for superplastic forming parts such as aircraft engine blades.
D. Intermetallic compounds
This is a new type of material, it may completely replace the superalloy. Superalloys will generate a Y phase under high temperature work. Studies have shown that this phase is the main reason that makes the material have high temperature strength, creep resistance and high temperature oxidation resistance. Therefore, people started the research of intermetallic compound materials. Intermetallic compounds, whose density is only half of that of superalloys, can at least be used in low-pressure sections to replace superalloys.
E. High-performance composite materials
The GE90-115B engine produced by General Motors of the United States uses a carbon fiber polymer blade and a titanium alloy blade edge. There are 22 turbofan blades, each weighing 30-50 pounds, and the total weight is 2000 pounds. It can provide the best thrust-to-weight ratio and is currently the largest aircraft jet engine blade used in Boeing 777 aircraft.