Titanium alloy has a series of advantages such as high specific strength, good corrosion resistance and high temperature resistance, etc. It can be used in various ways of parts forming, welding and machining, so it has been widely used in advanced aircraft and engines. Nowadays, the percentage of titanium alloy content in aircraft structure weight has become one of the important signs to measure the advanced degree of aircraft materials. Titanium makes up 39 percent of the f-22's structural weight. The use of titanium alloy in foreign civil aircraft also increases with the improvement of aircraft design and performance.
High damage tolerance is an important material performance index for new generation fighter (including high thrust ratio engine) with long life, high maneuverability, low cost and damage tolerance design. The United States took the lead in applying the concept of damage safety design and damage tolerance design criteria to advanced fighter aircraft. F-22 fighter aircraft adopted a large number of damage tolerance titanium alloy and its large integral components to meet the design requirements of high weight reduction and long life.
The ti-6al-4v ELI has been used in oversized forgings on the U.S. c-17 military transport aircraft, and the high-strength titanium ti-6-22-22 S has also been used in key parts on c-17 aircraft, such as the horizontal tail joint (swivel shaft).The use of these two titanium alloys has given large transport aircraft a life span of more than 60,000 flight hours. In Europe, the A380 is the first aircraft to have all-titanium racks, and future A350 models will also have all-titanium racks.
