High temperature titanium alloy material
High-temperature titanium alloys have been widely used in aeroengines due to their excellent thermal strength and high specific strength. Parts produced from them include fan discs, blades, compressor discs, etc. Developed countries in the aviation industry such as Europe and the United States have successively developed high-temperature titanium alloys for use in environments of 350°C to 600°C, and the use temperatures have gradually increased. The new high-temperature titanium alloys that have been successfully used in military and civil aircraft engines include: British IMI829 and IMI834 alloys, American Ti1100 alloys, BT36 alloys, etc., with operating temperatures of 550°C to 600°C. Foreign countries are still conducting in-depth research on the basis of traditional high-temperature titanium alloys. In addition, Ti3Al (α2) and TiAl (γ) intermetallic compounds based on titanium aluminum compounds have begun to attract attention and become the most competitive materials for future aerospace engines and aircraft structural parts.
Its biggest advantages are good high-temperature performance (the maximum operating temperatures are 816°C and 982°C respectively), strong oxidation resistance, good creep resistance and lighter weight. Currently, two titanium alloys based on Ti3Al, Ti–21Nb–14Al and Ti–24Al–14Nb–3V–0.5Mo, have begun mass production in the United States.
In the past 20 years, our country has also developed various brands of high-temperature titanium alloys, mainly including Ti-55, Ti-60, Ti-600 and 7715 series alloys.
High strength titanium alloy
High-strength titanium alloys generally refer to titanium alloys with a tensile strength of more than 1,000MPa. Applications in aircraft mainly include important structural parts such as the torsion arms and pillars of the landing gear and the load-bearing partition beams of the fuselage. At present, the high-strength titanium alloys that represent the international advanced level and have practical applications in the aviation field mainly include β-type titanium alloy Ti-1023, Ti-15-3, β-21S, α-β two-phase titanium alloy BT22 and my country's TB10 etc. Our country has successfully developed high-strength titanium alloys such as TB6, TB8, TB10, and TC21, among which TC21 and TB10 (Ti-5Mo-5V-2Cr-3Al) are the most typical. TC21 titanium alloy has high strength, high toughness, high damage tolerance (lower fatigue crack growth rate da/dN value and high fatigue crack growth threshold value ΔKth) and fatigue performance (better than ordinary TC4, TA15 and other medium Strength titanium alloy) and other comprehensive performance matching, it is currently the titanium alloy material with the best comprehensive mechanical properties matching of high-strength and tough titanium alloys in my country.
TB10 alloy is a high-strength, high-toughness, nearly β-type titanium alloy. It has the advantages of high specific strength, good fracture toughness, and high hardenability. It has been practically used in my country's aviation field.
Flame retardant titanium alloy
In order to solve the "titanium combustion" problem of titanium alloy materials used in aerospace engines and meet the needs of high thrust‑to‑weight ratio engines, the United States has actively carried out the development of flame‑retardant titanium alloys since the 1970s, and have successfully developed its own flame‑retardant titanium alloy. Flame‑retardant titanium alloys in other countries are basically in the research stage and have few practical applications. At present, the more typical alloy abroad is the American Ti‑V‑Cr flame‑retardant titanium alloy AlloyC. AlloyC flame‑retardant titanium alloy has been successfully used in the high‑pressure compressor casing, guide vanes and vector tail nozzles of the F119 engine.
