At the beginning of the 20th century, people invented the airplane, and since then started a new era of human aerospace. Early aircraft manufacturing materials were mainly wood, but it was fragile, breakable and perishable. With the application of aircraft in the First and Second World Wars, people’s requirements for aircraft performance became higher and higher, so the plasticity was good. , Aluminum alloy airplanes with high strength, easy processing, and lighter weight came into being, but aluminum alloy airplanes have the shortcomings that they are not resistant to high temperatures and wear. In order to solve the above problems, scientists have been looking for a metal that can replace aluminum alloy to make aircraft skeletons, so titanium entered the field of vision of aircraft manufacturers.
It can be seen from the properties of titanium that titanium has a low density, high thermal and endurance strength, low sensitivity to crack propagation under vibration load and impact load, and good corrosion resistance. Titanium and its alloys the strength is equivalent to the strength of steel, but the weight is 57% of steel. Therefore, it is a trend to use titanium alloys to replace aluminum alloys to manufacture aircraft. In modern aircraft manufacturing, people generally use aircraft engines and shell structures. High-strength titanium and titanium alloys replace aluminum alloys.
At present, the proportion of aircraft made mainly of titanium alloy in the aviation field has an overwhelming advantage, especially the US military aircraft are mostly titanium alloy products. Such as its hypersonic reconnaissance aircraft SR-71. The mass of titanium alloy in this aircraft accounted for 92% of the total mass of the aircraft, and B titanium alloy was used for the first time. For another example, the fourth-generation fighter F-22 of the United States, space planes, and titanium accounted for 50% to 60%. In addition, the proportion of titanium in F-14, F-15, F-18 Hornet, F-117 Nighthawk, B-1 bomber, and B-2 bomber is 24%, 27%, 13%, 25%, 22%, and 26%. In the weight composition of supersonic aircraft, the amount of titanium used accounts for more than 95%. Facts have proved that it is difficult to develop supersonic aircraft without the use of titanium alloys, because aircraft made of titanium alloys can reduce the mass by about 5t compared with aluminum alloys. Under the condition of the same passenger capacity, the titanium alloy aircraft’s the speed increased greatly. In addition, in the development of rockets and other aero-engines, the proportion of titanium used is getting higher and higher, generally accounting for 18% to 25% of the total weight. According to research, half of the world’s titanium output is used in aero engines. On the circle.