Titanium alloy can be divided into heat resistant alloy, high strength alloy, corrosion resistant alloy (titanium-molybdenum, titanium-Palladium alloy, etc.), low temperature alloy and special function alloy (ti-iron hydrogen storage material and ti-nickel memory alloy) and so on.
Although titanium and its alloy application history is not long, but because of its superior performance, has won a number of honorable titles. The first award was space Metal. It is light, strong and high temperature resistant, especially suitable for the manufacture of aircraft and various spacecraft. About three-quarters of the titanium and titanium alloys produced in the world today are used in the aerospace industry. Many parts that used to be made of aluminum alloy were made of titanium alloy.
Titanium alloy is mainly used in aircraft and engine manufacturing materials, such as forged titanium fans, compressor discs and blades, engine hoods, exhaust devices and other parts, as well as structural frame parts such as girders and frames of aircraft. Spacecraft mainly use titanium alloy high specific strength, corrosion resistance and low temperature performance to manufacture a variety of pressure vessels, fuel tanks, fasteners, instrument straps, frames and rocket housing. Man-made earth satellite, lunar module, manned spacecraft and space shuttle also use titanium plate welding pieces.
The top speed of modern aircraft has reached 2.7 times the speed of sound. At supersonic speeds this fast, the plane rubs against the air and generates a lot of heat. At 2.2 times the speed of sound, the aluminum alloy will not survive. High temperature resistant titanium alloys must be used. When the thrust-weight ratio of aero-engine increases from 4 ~ 6 to 8 ~ 10, and the compressor outlet temperature increases correspondingly from 200 ~ 300℃ to 500 ~ 600℃, the low-pressure compressor discs and blades originally made of aluminum must be changed to titanium alloy. In recent years, scientists have made new progress in the research on the properties of titanium alloys. The original titanium alloy composed of titanium, aluminum and vanadium has a maximum working temperature of 550℃ ~ 600℃, while the newly developed TiAl alloy has a maximum working temperature of 1040℃. High pressure compressor discs and blades made of titanium alloy instead of stainless steel can reduce the weight of the structure. For every 10 per cent weight loss, 4 per cent fuel savings can be achieved. For a rocket, one kilogram of weight can increase its range by 15 kilometers.
