Spacecraft in ultra high temperature, ultra low temperature, high vacuum, high stress, strong corrosion and other extreme conditions, in addition to relying on excellent structural design, but also depends on the excellent characteristics and functions of materials. Titanium alloys are the products of space products which are called "cosmic metal" and "space metal"". According to the demand of aerospace products for materials, titanium alloys are developing in the following areas:
1. High strength and toughness titanium alloy
The successful example is the development of two-phase high strength and toughness of Ti62222S titanium alloy, with good strength and ductility of the material, fracture strength and yield strength were higher than 1300MPa and 1200MPa, and its high temperature performance is also very good. In addition, Ti62222S also has higher fracture toughness and damage tolerance, and the fatigue crack growth rate as compared with alloy Ti6Al4V is better than that of alloy Ti6Al4V. The elastic modulus and superplastic forming properties can be substituted by Ti6Al4V.
2. High temperature titanium alloy
Supersonic cruise missile, hypersonic cruise missile, reusable launch vehicle, and the research and development of reusable suborbital transatmospheric vehicles, requirements must be able to use titanium alloy at 600 degrees and above under high temperature, which requires the titanium alloy must have excellent high-temperature properties.
3. Cryogenic titanium alloy
With the rapid development of space technology, the application of titanium alloys in low temperature and extremely low temperature environment is increasing, and the development of low temperature titanium alloys is of great importance. It has been found that the low temperature properties of Ti alloy can be improved by reducing the interstitial elements such as H, O and N and the content of Al, so that it can be used for a long time under the 20K temperature environment.
