The improvement of aero-engine performance is closely related to the collaborative application of new high-temperature titanium alloys and advanced structural design. Since the 1990s, China has accelerated the research process of new high-temperature titanium alloy materials and developed new materials such as 550 ℃ high-temperature titanium, 600 ℃ high-temperature titanium, burn-resistant titanium alloy, and Ti-Al Intermetallic Alloys.
In terms of high-temperature titanium alloys, the first generation of 550 ℃ TA12 and 600 ℃ Ti60 containing rare earth Nd independently developed in China have excellent thermal strength properties, However, due to the lack of research reserves in welding technology and the easy segregation of rare earth phase at the grain boundary in the weld area, which is easy to cause brittle fracture of the joint, these problems have not been effectively solved and have not been applied in aero-engine.
Based on the electron concentration theory, in the appropriate use of α 2 phase strengthening and silicide precipitated phase strengthening at the same time, Nb and Ta elements were added to the Ti-Al-Sn-Zr-Mo-Si alloy system to further improve the effect of the multi-element composite solid solution strengthening. The second generation of 550 ℃ TA32 and 600 ℃ TA29 and TA33 with good thermal strength, forging, and welding properties were developed.TA29 and TA33 titanium alloys have little difference in composition, while the difference in performance level mainly depends on process control factors.
On the basis of the second generation of 600 ℃ high-temperature titanium alloy, a 650 ℃ Ti65 was further developed by adding W element and increasing the content of TA element, so that the long-term service temperature of the solution strengthened high-temperature titanium alloy is expected to break through the traditional 600 ℃ thermal barrier temperature. In terms of research on flame retardant titanium alloys, two temperature resistant ti-v-cr series flame retardant titanium alloys have been developed, namely TB12 flame retardant titanium alloy (Ti40) long used at 500 ℃ and tf550 flame retardant titanium alloy long used at 550 ℃. The study on the flame retardancy and comprehensive mechanical properties of TB12 and tf550 titanium alloys shows that the two alloys have similar flame retardancy, and the difference in V content mainly affects the thermal strength of the materials. In the research of Ti-Al intermetallic alloys（ α 2 + O + B2) three-phase Ti3Al alloy, Ti2AlNb alloy based on O phase, and The study of γ-TiAl alloy shows that the long-term service temperature of Ti-Al intermetallic compound alloy reaches 650 ~ 800 ℃.
