The specific strength (strength to weight ratio) of
titanium and its alloys is very high among metal structural materials. Its strength is equal to that of steel, but its weight is only 57% of that of steel. In addition, titanium and its alloy of high heat resistance, at 500℃ in the atmosphere can still maintain a good strength and stability, short time working temperature can be even higher. Aluminum at 150℃, stainless steel at 310℃ will lose the original mechanical properties. When the aircraft, rocket high-speed flight, the engine and the surface temperature is quite high, aluminum alloy is not competent, at this time, the use of titanium alloy is very suitable. It is because titanium and its alloy have the comprehensive excellent performance of strong strength, light weight and strong heat resistance, when it is used to replace other metals in aircraft manufacturing, it can not only extend the service life of the aircraft, but also can reduce its weight, so as to greatly improve its flight performance. Therefore, titanium is one of the promising structural materials in aviation industry and space industry.
Titanium and its alloys are used mainly in aircraft engines and airframes in the aviation industry. Generally speaking, aircraft with a Mach number less than 2 use a portion of titanium and its alloy for the engine and aluminum alloy for the fuselage. An aircraft with a Mach number of 2 USES more titanium in its engines and some of its fuselage. For aircraft with Mach number greater than 3.5, the engine inlet temperature is too high to use titanium alloy, but the amount of titanium used in the airframe is significantly increased.
Titanium and its alloys have good low temperature resistance, even in - under the temperature of 250 ℃, it still has the high impact strength, resistance to high pressure resistance to vibration, thus, titanium and its alloys on the rockets and spacecraft is not only used in the manufacture of engine casing and structural elements, and used in the manufacture of high pressure vessel, such as high pressure cylinders, cryogenic liquid tank, etc.
