Application of titanium plate titanium materials in passenger aircraft
European Airbus' A3XX passenger aircraft, American Boeing's B77X aircraft, COMAC's C919, and CR929 aircraft produced by Sino-Russian joint ventures all use titanium materials in large quantities. structure.
The development of the C919 large passenger aircraft, which was completely independently developed by China, began in 2008. On November 2, 2015, the main model moved off the sequential construction system and went through practice run at Shanghai COMAC. The principal flight occurred on May 5, 2017. The main exchange flight was completed on November 10, and the second C919 large aircraft successfully made its first flight at Shanghai Pudong Airport on December 17, marking the entry of domestic large aircraft into a new stage of comprehensive test flight. Although the materials used in the prototype are all from abroad, they are mainly used to obtain airworthiness certification. Starting from the No. 2 machine, the use of domestic materials has increased one batch at a time, and it is getting more and more year by year.
The main technical parameters of the C 919 large aircraft are shown in the table.
Titanium materials have been widely used in the manufacture of large civil aircraft. Some key components of the landing gear and wheels are forged from titanium alloy, and a small number of parts are also forged from 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. Among civil aircraft manufactured in China, titanium is used in the largest amount. Which parts are made of titanium: the nose is made of Ti-6Al-4VEVI forgings; the suspension is made of Ti-6Al-4V alloy forgings, plates and titanium alloy 55531 forgings; the tail is made of Ti-6Al-4V alloy forgings; the outer wing It uses Ti-6Al-4V alloy forgings and plates; the center wing uses Ti-6Al-4V EL1 alloy forgings; the landing gear system uses Ti-6Al-4V alloy forgings.
Ti-6Al-4V (GR5, GB/T3620) is a medium strength (>900MPa) α+β alloy. It was successfully developed by the Watertown Arsenal in the United States in 1954 and is widely used in the aviation field. In the aerospace field, its semi-finished product production accounts for 55%-65% of the world's total titanium production. Used to produce various aerospace vehicle forgings and plates. Because of its excellent comprehensive properties, moderate price, and early molding, it is the alloy with the most research, longest use time, and widest application range. Therefore, this alloy has maintained strong vitality since its birth 67 years ago. The grade of this alloy is GR5 in my country, Ti-6Al-4V by American Titanium Company (Timet), RMI 6Al4V by American Active Metal Company, IMI318 by British Titanium Metal Company, BT6 in Russia, and Sumitomo Metal Company of Japan. ST-AI40, French TA6V, and German Krupp LT31. GR5 alloy is used in the annealed state and can be strengthened by heat treatment, but its weldability is poor. The "ELI" in Ti-6Al-4V ELI stands for Extro-Low Interstitial titanium alloy, which is an α and α+β titanium alloy suitable for low temperature use. Their strength properties increase with decreasing temperature. Toughness rarely decreases with temperature and can be used to manufacture low-temperature structural parts. The oxygen content of low-temperature titanium alloys is very low, from 0.2% to ≤0.12% of ordinary grade oxygen, and can be used at extremely low temperatures (<77K). Typical alloys are Ti-5Al-2.5Sn (ELI) and Ti-6AI-4V (ELI). Ti-5Al-2.5Sn ELI is an American alloy introduced in the early 1960s. China successfully copied it in the late 1970s, under the brand name GR6 (Chinese military standard GJ B495). Ti-5Al-2.5Sn ELI alloy is particularly suitable for liquid fuel storage tanks operating at -255°C. Both titanium alloys are well supplied by China Baoti Group.
The A380 large passenger aircraft of the European Airbus Company is the largest wide-body civil aircraft in the world and the aircraft that uses the most titanium materials. The net mass of titanium alloy components accounts for approximately 10% of the total net mass of the entire machine. The titanium material consumption of a single aircraft is approximately 65 tons. . The main parts made of titanium alloy are: engine pod, skin, accessories, connecting ring wing, front bulkhead, shaft between inner flaps and wing, hinge rail raceway, trailing edge, shaft assembly, hinge Three stiffeners, engine section pylons, propulsion components, leading edge, front bracket, part of the landing gear and weldable wing rails.
