Titanium alloy has high strength and low density, good mechanical properties, good toughness and corrosion resistance.In addition, titanium alloy process performance is poor, difficult cutting, in hot processing, very easy to absorb hydrogen, oxygen, nitrogen, carbon and other impurities.And wear resistance is poor, the production process is complex.Industrial production of titanium began in 1948.The need of aviation industry development makes the titanium industry develop at an average annual growth rate of about 8%.The world's annual production of titanium alloy processing materials has reached more than 40,000 tons, titanium alloy brand nearly 30 kinds.The most widely used titanium alloys are Ti-6al-4V (TC4), Ti-5al-2.5SN (TA7) and industrial pure titanium (TA1, TA2 and TA3).

Titanium alloy is mainly used in the production of aircraft engine compressor parts, followed by rockets, missiles and high-speed aircraft structures.By the mid-1960s, titanium and its alloys had been used in the general industry, making electrodes for electrolysis, condensers for power stations, heaters for petroleum refining and seawater desalination, and environmental pollution control devices.Titanium and its alloys have become corrosion-resistant structural materials.In addition, it is also used to produce hydrogen storage materials and shape memory alloys.

China began to study titanium and titanium alloys in 1956.In the mid-1960s, the industrial production of titanium began and TB2 alloy was developed.

Titanium alloy is a new important structural material used in aerospace industry. Its specific gravity, strength and service temperature are between aluminum and steel, but it has higher strength than aluminum and steel and excellent seawater corrosion resistance and ultra-low temperature performance.In 1950, the U.S. first used f-84 fighter-bombers as rear fuselage heat shield, wind shield, tail cover and other non-bearing components.Since the 1960s, the use of titanium alloy has shifted from the rear fuselage to the middle fuselage, partially replacing the structural steel to manufacture insulation frame, beam, flap slide track and other important bearing components.The use of titanium alloy in military aircraft is increasing rapidly, reaching 20% ~ 25% of the structural weight of aircraft.Since the 1970s, civil aircraft began to use a large number of titanium alloy, such as the Boeing 747 with more than 3640 kilograms of titanium.Aircraft with Mach Numbers greater than 2.5 use titanium mainly to replace steel to reduce structural weight.For another example, the US SR-71 high-altitude high-speed reconnaissance aircraft (flying Mach 3 at an altitude of 26212 meters), with titanium accounting for 93% of the weight of the aircraft structure, is called "all-titanium" aircraft.When the thrust ratio of the aeroengine increases from 4 ~ 6 to 8 ~ 10, the compressor outlet temperature increases from 200 ~ 300°C to 500 ~ 600°C accordingly, the low pressure compressor disk and blade made of aluminum must be replaced by titanium alloy, or titanium alloy is used instead of stainless steel to make high pressure compressor disk and blade, in order to reduce the structural weight.In the 1970s, the amount of titanium alloy in aero-engines generally accounted for 20% ~ 30% of the total structural weight, mainly used for manufacturing compressor parts, such as forging titanium fan, compressor disc and blade, casting titanium compressor casing, intermediate casing, bearing housing, etc.The high specific strength, corrosion resistance and low temperature resistance of titanium alloy are used to manufacture various pressure vessels, fuel tanks, fasteners, instrument straps, frames and rocket shells.Titanium alloy plates are also used to solder satellites, lunar modules, manned spacecraft and space shuttles.