Applications of titanium products in aerospace

1. Application of titanium alloy in aerospace field

1.1 Application scope of titanium in early aerospace industry development

Titanium alloy materials used in aviation and aerospace are called titanium alloy castings. They have a wide range of applications, including object joints, rivets, and castings. In the process of making aircraft, titanium alloy is mainly used in the components of engine compressor components, followed by the development of rockets and some weapon structural parts. In the mid-21st century, titanium and its titanium alloys have been widely used in general industrial fields.

1.2 Innovation of titanium alloy in aircraft frames

Titanium alloy is a new important structural material used in the aerospace industry. Its specific gravity and operating temperature are between those of aluminum and steel, but its specific strength is high and it has excellent resistance to seawater corrosion and ultra-low temperature performance. Since the 1960s, the use of titanium alloys has moved from the rear fuselage to the middle fuselage, partially replacing structural steel in the manufacture of important load-bearing components such as bulkheads, beams, and flap slide rails. With the continuous construction of national defense forces, the use of titanium alloys in military aircraft has increased rapidly. In the total weight of the entire aircraft structure, the weight of titanium alloy accounts for 20% to 25%. Over time, in order to meet the needs of society, civil aircraft have also begun to use titanium alloys in large quantities. For example, on the Boeing 747 passenger aircraft, the weight of titanium has reached more than 3,600 grams. For those aircraft with a Mach number less than 2.5, titanium is mainly used to replace the use of steel, thereby reducing the weight of the aircraft structure. Another example is the American SR-72 series of high-altitude and high-speed reconnaissance aircraft. Its flight Mach number is 3.0 and its flight altitude reaches 26,200 meters. In its construction process, titanium alloy is an important structural material, and titanium alloy is even more important. Accounting for 91% of the aircraft's structural weight, it is called a "full titanium" aircraft.

1.3 titanium alloy air compressor

When the thrust-to-weight ratio of the aeroengine increases from 4~6 to 8~10, the temperature of the compressor outlet will correspondingly increase from 200℃~300℃ to 500℃~600℃. Then the air compressor originally made of aluminum Low-pressure compressor disks and blades must be made of titanium alloys or titanium alloys must be used instead of stainless steel to make high-pressure compressor disks and blades, so as to reduce the weight of the aircraft structure. Since the 1970s, the amount of titanium alloy used in aeroengines has generally accounted for 20% to 30% of the total weight of the structure. It is mainly used to manufacture compressor parts, such as forged titanium fans, compressor discs and blades, and cast titanium compressors. casing, intermediate casing, bearing housing, etc. Spacecraft mainly utilize the high specific strength, corrosion resistance and low temperature resistance metal properties of titanium alloys to manufacture various pressure vessels, fuel tanks, fasteners, instrument straps, frames and rocket casings. Artificial earth satellites, lunar modules, manned spacecraft and space shuttles also use titanium alloy plate welding parts.

1.4 Application of titanium alloy spinning parts

In the field of aerospace, titanium rods and titanium forgings are used in aerospace vehicle systems not only because titanium alloys have strong structural properties and good physical properties, but more importantly, they are lightweight and sophisticated. . The quality reliability of new titanium alloy spinning parts requires data analysis of multiple tests. Because the forming of titanium alloy plates is extremely complex, Aerospace 703 uses TC4 as the basis of titanium alloy plates, and uses a combination of general spinning and powerful spinning to create a new type of titanium alloy hemispherical sphere. At the same time, TC3 and TC4 are used as titanium alloy plates. According to the ingredients of the alloy plate, two new types of titanium alloy hemispheres were produced using hot spinning as a technical means.

1.5 Application in gas engines

In the aerospace field, titanium alloys have another major application area, which is their application in aircraft engine manufacturing. So far, 1/3 of the structural mass of gas turbine engines used in modern aircraft in our country is composed of titanium alloys. However, according to relevant data, it was found that as early as the 1940s and 1950s, some industrially developed countries, such as the United States and the United Kingdom, applied titanium alloy technology to improve the performance of jet engines in the early production of aircraft. Structural components. The earliest titanium alloy engine component was the compressor blade, and then titanium alloy compression discs also developed rapidly. Today, the fan blades used in most jet engines are made of new titanium alloys.

1.6 Application of high temperature titanium alloys

Because high-temperature titanium alloys have strong thermal strength and high specific strength characteristics, they have been widely used in aerospace engines. High-temperature titanium alloys are mainly used in aircraft engines for engine fans, blades, precision instruments or navigators. The use of titanium alloy to replace the original high-temperature alloy reduces the structural weight of the compressor by 30% to 35%. Over the years, in order to meet the needs of high-performance engines, a sound titanium alloy system has been formed

2. Difficulties in processing titanium alloys in the aerospace industry

At present, the continuous development of the aerospace industry, in order to reduce the weight of aircraft, has prompted an increasingly severe demand for materials that meet its standards in the development process of aerospace. Compared with ordinary materials, titanium and titanium alloys Alloys are composite materials that are lighter, stronger and tougher. However, in the process of processing, especially in the cutting process, they each face different processing problems and troubles. During machining work, manufacturers must achieve the highest possible level of quality. Even if there are concerns about the cost of parts and components, in many cases, how to produce high-quality parts and components is the priority, followed by how to improve productivity.

3. Conclusion

At present, my country's scientific and technological means have basically met the requirements of spinning technology for small titanium alloys. However, because titanium alloy is a new type of metal, especially because it has high chemical activity, it is very susceptible to contamination by hydrogen, oxygen, and nitrogen, making it difficult to smelt and process it, making the production cost relatively high. In the application process of titanium alloy, it has some other excellent properties that have not been fully verified, resulting in certain limitations in its use. Although the development of aerospace is faced with the challenge of using high-performance composite materials, with the rapid development of the aerospace industry, new titanium alloy technology will enter a new development period, and its spin forming technology will It will have broader development space and application scope in aerospace and other fields.