Application Of Titanium Alloy Materials in Large Airliners

A number of structural parts made of titanium are used in the A3XX airliners of Europe's Airbus, the B77X aircraft of Boeing Aircraft Company (Boeing), and the C919 of Commercial Aircraft Corporation of China (COMAC), and the CR929 produced by a Sino-Russian joint venture.
The development of China's fully independently developed C919 large passenger aircraft began in 2008, and the first prototype was rolled off the production line and tested at Commercial Aircraft Corporation of China Limited in Shanghai on 2 November 2015, the first flight was made on 5 May 2017, the first turnaround flight took place on 10 November, and the second C919 large aircraft made its maiden flight at Shanghai Pudong Airport on 17 December, marking the successful debut of a domestically produced large The aircraft has entered a new stage of comprehensive test flights. Although all the materials used in the prototype are foreign goods, it is mainly for the need to obtain airworthiness certification, from the second aircraft, the amount of domestic materials will be more than a batch of more than one, more than one year.
Titanium has been widely used in the manufacture of large-scale civil aircraft, landing gear and some key parts of the wheel are forged with titanium alloy, there are also a small number of parts forged with aluminium alloy. In the C919 large aircraft, the net mass of titanium alloy parts and components accounted for about 10% of the total net mass of the aircraft, the largest amount of titanium in China-made civil aircraft, which parts for titanium (see Figure 1): the nose, with Ti-6Al-4VEVI forgings; hanging, with Ti-6Al-4V alloy forging, plate and titanium alloy 55531 forgings; tail wing with Ti-6Al- 4V alloy forgings; outer wings with Ti-6Al-4V alloy forgings and plates; centre wing with Ti-6Al-4V ELl alloy forgings; landing gear system with Ti-6Al-4V alloy forgings.
Ti-6Al-4V (TC4, GB/T3620), a medium-strength (>900MPa) α + β-type alloy, was developed by the U.S. Watertown (watertown, also known as Watertown) Arsenal in 1954, is widely used in aerospace, and its semi-finished products accounted for 55%-65% of the world's total production of titanium, which is used for the production of a variety of aerospace vehicles Because of its excellent comprehensive performance, moderate price, early moulding, the most in-depth research, the longest time of use and the widest range of applications, the alloy has maintained a vigorous vitality since its birth 67 years ago. This alloy China's brand name for the TC4, the United States titanium company (Timet) brand for the Ti-6Al-4V, the United States of America active metal company for the RMI 6Al4V, the British titanium metal for the IMI318, Russia's for the BT6, Japan's Sumitomo Metals for the ST-AI40, France's TA6V, the German Krupp company for the LT31. TC4 alloy in the annealed TC4 alloys are used in annealed condition and can be heat-treated for strengthening, but have poor weldability. ti-6Al-4V The "ELI" in ELI stands for Extro-Low Interstitial titanium alloy, which are α and α + β titanium alloys that are suitable for low-temperature use, and whose strength properties increase with decreasing temperature. They are suitable for use at low temperatures. Their strength properties increase as the temperature decreases, and their toughness rarely decreases as the temperature decreases, so they can be used to manufacture low-temperature structural components. Low-temperature titanium alloys have very low oxygen content, from 0.2% oxygen to ≤0.12%, can be used at very 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 that was introduced in the early 1960s and copied in China in the 1970s under the brand name TA7 (Chinese military standard GJ B495). Ti-5Al-2.5Sn ELI is particularly suitable for liquid fuel tanks that operate at -255°C. Both of these titanium alloys are well supplied by China Baoti Group.
European Airbus A380 large passenger aircraft, is the world's largest wide-body civilian aircraft, but also the largest amount of titanium, titanium alloy parts and components of the net mass of about 10% of the total net mass of the aircraft, a single machine titanium dosage of about 65 tonnes. Titanium alloy parts are mainly (see Figure 2): engine pods, skin, attached to the mouth, connecting the ring wing, the front bulkhead, the shaft between the inner flap and the wing, the folding leaf rail track, trailing edge, shaft parts, folding leaf 3 reinforcement, engine part of the hanger, propulsion components, leading edge, front bracket, part of the landing gear, weldable wing (bar) rail.