Why is titanium the most suitable material for engines?
For all countries around the world, aviation R & D and manufacturing industry is a system engineering, which often involves many industries and fields. Especially in the field of military industry, a fighter is composed of a large part system, and the most important thing is the engine. In the core technology of engine R & D, materials are the prerequisite. In recent years, titanium alloy as engine material has become a global consensus. With the continuous improvement of independent R & D technology in China, Chinese researchers have also begun to realize the development and utilization of this kind of high-tech materials. It is worth mentioning that as a large resource country, China has abundant titanium metal deposits. With the continuous improvement and upgrading of titanium alloy technology, including j-20, many new fighters in China are expected to modify titanium alloy engines in the future, and further improve the performance level.
Why is titanium most suitable as engine material? First of all, the high strength of titanium metal is unique among many metal elements, far more than the common aluminum alloy, magnesium alloy, stainless steel, etc. At the same time, it can keep stable work for a long time under the high temperature environment of 450-500 ℃, and it also has the advantages of good corrosion resistance, good low temperature performance, large chemical activity, small thermal conductivity and small elastic modulus. It can be said to be the most suitable manufacturing material for Aeroengine. The data show that three quarters of titanium alloy materials produced in the world are used in the aerospace industry.
as we all know, with the continuous surpassing of aviation R & D technology, the requirements for engines of the latest generation of aircraft, whether civil aviation or military, are increasing. Especially, the most critical performance - push weight ratio, has become a standard performance index of an advanced aircraft. From the early jet era, there was only 2-3 thrust to weight ratio, and now the supersonic age reached more than 10 thrust weight ratio level, which is due to the continuous update and replacement of modern aeroengine materials. From the perspective of Aeronautics theory, it is the most important way to improve the thrust weight ratio of engine and reduce its weight. Because the density of titanium metal is only 40% of steel, but it has the same strength, its melting point of 1668 ℃ is also the best high temperature metal material for aeroengine.
Since then, China has been catching up with the European and American powers in the independent research and development of engines. Especially in the research and exploration of high temperature resistant titanium alloy materials, the gap between the two countries has been shortened gradually. Before, with titanium alloy as the material, our research team has successively developed tc-4, TC-11, tc-14 and other aeroengine materials, especially the appearance of high temperature titanium alloy ta-12 with 550 ℃ resistance in 1990s, which laid a solid foundation for the development of the fourth generation of domestic fighters.