Titanium alloy can be divided into: heat resistant alloy, high strength alloy, corrosion resistant alloy (Ti-Mo, Ti-Pd alloy, etc.), low temperature alloy and special function alloy (Ti-iron hydrogen storage material and Ti-nickel memory alloy).
Although the history of titanium and its alloys is not long, but because of its extraordinary properties, it has won a number of honorable titles. The first one to win the title is 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 world's titanium and titanium alloys are used in the aerospace industry. Many parts that used to be made of aluminum alloy were converted to titanium alloy.
Titanium alloy is mainly used in aircraft and engine manufacturing materials, such as forged titanium fan, compressor disc and blade, engine hood, exhaust device and other parts as well as aircraft beam frame and other structural parts. Spacecraft mainly use titanium alloy high specific strength, corrosion resistance and low temperature resistance to manufacture a variety of pressure vessels, fuel tanks, fasteners, instrument binding, frame and rocket housing. Titanium alloy plate welds are also used for artificial Earth satellites, lunar modules, manned spacecraft and space shuttles.
The top speed of modern aircraft has reached 2.7 times the speed of sound. Flying at supersonic speeds that fast would cause the plane to rub against the air and generate a lot of heat. At 2.2 times the speed of sound, aluminum alloys can't withstand it. High temperature resistant titanium alloys must be used. When the thrust-weight ratio of the aeroengine is increased from 4 ~ 6 to 8 ~ 10, and the temperature of the compressor outlet correspondingly increases from 200 ~ 300℃ to 500 ~ 600℃, the original low pressure compressor disc and blade made of aluminum must be changed to titanium alloy. In recent years, scientists have made new progress in the study of titanium alloy properties. The original titanium alloy composed of titanium, aluminum and vanadium has a maximum working temperature of 550℃ ~ 600℃, but the newly developed aluminum titanium (TiAl) alloy has a maximum working temperature of 1040℃. The use of titanium alloy instead of stainless steel in the manufacture of high-pressure compressor discs and blades can reduce the weight of the structure. For every 10 percent reduction in aircraft weight, it saves 4 percent in fuel. For a rocket, a 1kg reduction in weight can increase its range by 15km.
