Titanium has been widely used in the manufacture of large civil aircraft. Some key parts of landing gear and wheels are forged with titanium alloy, and a small number of parts are forged with aluminum alloy. In the C919 large aircraft, the net mass of titanium alloy parts accounts for about 10% of the total net mass of the aircraft, and the largest amount of titanium is used in civil aircraft made in China. Which parts are made of titanium (see Figure 1): machine The head uses Ti-6Al-4VEVI forgings; the suspension uses Ti-6Al-4V alloy forgings, plates and titanium alloy 55531 forgings; the tail uses Ti-6Al-4V alloy forgings; the outer wings use Ti -6Al-4V alloy forgings and plates; Ti-6Al-4V ELl alloy forgings are used for the central wing; Ti-6Al-4V alloy forgings are used for the landing gear system
Ti-6Al-4V (
Gr.5, GB/T3620) is a medium-strength (>900MPa) α+β-type alloy. Its semi-finished products account for 55%-65% of the world’s total titanium production. It is used to produce various aviation Spacecraft forgings and plates, because of their excellent comprehensive performance, moderate price, early forming, the most in-depth research, the longest use time, and the widest application fields, the grade is Ti-6Al-4V, which is also Gr.5 Titanium alloys and Gr.5 alloys are applied in the annealed state and can be strengthened by heat treatment, but their weldability is poor. “ELI” in Ti-6Al-4V ELI indicates that the extremely low interstitial titanium alloy (Extro-Low Interstitial titanium alloy) is an α and α+β titanium alloy suitable for use at low temperatures, and their strength properties increase as the temperature decreases. Toughness seldom decreases with temperature drop, so it can be used to manufacture low temperature structural parts. The oxygen content of low-temperature titanium alloy is very low, which is reduced from 0.2% oxygen of ordinary grade to ≤0.12%, and can be used at extremely low temperature (<77K). Typical alloys include
Ti-5Al-2.5Sn (ELI) and Ti- 6AI-4V (ELI).
The A380 airliner of Airbus is the largest wide-body civil aircraft in the world, and it also consumes the most titanium materials. The net mass of titanium alloy parts accounts for about 10% of the total net mass of the whole aircraft, and the consumption of titanium materials for a single aircraft is about 65 tons. . The parts made of titanium alloy are mainly (see Figure 2): engine pod, skin, attachment port, connecting ring wing, front bulkhead, shaft and wing between inner flaps, hinge rail raceway , trailing edge, shaft parts, hinge 3 ribs, part of the engine hanger, propulsion parts, leading edge, front bracket, part of the landing device, weldable wing (strip) rail.
