The selection and development of aeronautical materials are crucial to the manufacturing cost and overall performance of aircraft body structures. Looking back at history, China mainly relied on importation in the field of aviation equipment in the early days, and therefore most of the material systems followed foreign standards. However, in recent years, China has made remarkable progress in new aerospace materials technology, but still needs to face the gap with the international advanced level.
I. Titanium alloy: the "universal metal" in the field of aviation.
Titanium alloy is widely used in aerospace field due to its low specific gravity and high specific strength. In recent years, titanium alloy has not only been popularized in the field of military industry and aerospace, but also gradually expanded to many fields such as chemical industry, metallurgy, medical treatment and sports and leisure.
Internationally, advanced titanium alloys such as high-temperature titanium alloys, high-strength titanium alloys and flame-retardant titanium alloys have been widely used in aircraft structural parts and engine components. For example, the high-temperature titanium alloys Ti-6242S and Ti-1100 from the United States, as well as IMI834 from the United Kingdom and BT36 from Russia, have shown excellent performance in high-temperature environments.
In China, the independently developed Ti-60 alloy is a 600°C high-temperature titanium alloy with excellent thermal stability and high-temperature creep properties. In addition, high-strength structural titanium alloys developed by China at the beginning of the 21st century, such as the near-beta titanium alloy Ti-B18 and the sub-stabilized beta titanium alloy Ti-B20, have reached a high level of tensile strength. China has also made remarkable progress in flame-retardant titanium alloys, such as the independently developed Ti-40 alloy, which has excellent flame-retardant and mechanical properties and has been developed to a semi-industrialized scale.
However, despite these achievements, China's titanium alloy industry still faces some challenges. For example, high-end titanium alloy products are still mainly imitated, with a low level of material development and a narrow range of applications. At the same time, the metallurgical quality is unstable, with fewer varieties and incomplete specifications, and the research on related supporting technologies is progressing slowly.
Second, high-temperature alloys: key materials for aircraft engines
High-temperature alloy is a kind of special alloy that can work stably in a high-temperature environment above 600 degrees Celsius, and it is the key material in the field of heat engine power such as aviation engine. According to the product process distinction, nickel-based high-temperature alloys in the high-temperature alloys in the dominant position, the production accounted for up to 80%.
High-temperature alloys are widely used in aero-engines, mainly for the manufacture of four major hot-end components such as combustion chambers, guides, turbine blades and turbine disks. The performance level of these components directly determines the overall performance of the engine. Therefore, the research and development and application of high-temperature alloys are of great significance to enhance the performance of aero-engines.
In China, the high-temperature alloy industry is still in the growth period, and the industry chain enterprises have a broad space for future development. However, compared with the United States and other developed countries, the number of Chinese high-temperature alloy production enterprises and production level still needs to be improved.
To summarize, China has made remarkable progress in the field of aviation materials technology, but still needs to face many challenges. In order to improve the overall performance of aviation equipment, China should continue to increase its R&D efforts in new material technologies and promote the application and development of advanced materials such as titanium alloys and high-temperature alloys. At the same time, it also needs to strengthen exchanges and cooperation with the international advanced level to jointly promote the progress of global aviation materials technology.
