Titanium alloy consumption for Chinese civil aircraft

 The annual growth rate of titanium alloy consumption for Chinese civil aircraft is about 6.5%. On November 14, 2019, the Aviation Industry Development Center of China (AVIC) released the "China Civil Aircraft Market Forecast 2019-2038", which pointed out that in the future, the world's civil aviation industry will continue to grow rapidly, and China will become the most dynamic and fastest developing civil aviation market.From the perspective of future development trend, the sustained and stable growth of the national economy, the rapid development of tourism, the acceleration of urbanization and the upgrading of national consumption are the main driving forces for the development of China's air transport market.It is estimated that China's air transport will maintain a relatively large growth rate from 2019 to 2038, with an average annual growth rate of 6.1% in passenger turnover (RPK) during the whole period, and passenger turnover will reach 3.4 trillion person-km in 2038.

It is predicted by the Development Center that in the next 20 years, the fleet structure of turbojet regional aircraft in "One Belt And One Road" region will change significantly, which is embodied in the proportion of 70-seat turbojet regional aircraft transport capacity will increase continuously in the next 5 years, while the proportion will decrease in the later period and eventually become stable.As the "One Belt And One Road" regional market matures, the frequency of flights will further increase, travel convenience and airline competition will lead to the development of smaller regional aircraft again, but ultimately the proportion of large regional aircraft will be high compared to the global level.

Xi 'an Aircraft Civil Aircraft Co., Ltd., a major manufacturer of regional turbojet in China, has paid 127 domestic and foreign customers for its "Xinzhou" series regional turbojet as of December 2020.At present, more and more countries along the "One Belt And One Road" and African countries have adopted the "Xinzhou" regional jet.Although China has built a relatively complete civil aviation system, there is still a big gap between China and foreign countries and developed countries. In 2020, the average per capita flight in China will be about 0.35 times, while the global average is 0.5 times, which is much lower than the 2.54 times in the United States and 0.93 times in Japan. Therefore, China's civil aviation industry still has great potential for development.It provides a great space for the development of titanium industry.

In the manufacturing of civil aircraft, titanium material is mainly used for engine and landing gear structure. In the landing gear system, some structural parts are subjected to huge impact force when landing on the ground, and must be forged with titanium alloy, using TC4 (Ti-6Al-4V) alloy. Its composition (mass %) :Al5.5 ~ 6.8, V3.5 ~ 4.5, the content of impurities is not more than Fe0.30, C0.10, N0.05, O0.20, other impurities 0.1 single, 0.4, the rest is Ti.The blank forging is 950℃ ~ 1150℃, the later forging temperature is about 950℃, and the fire deformation is 30% ~ 70%.The engine system is made of titanium alloy which can work at high temperature for a long time. It has high instantaneous strength and durable strength in the whole operating temperature range.It has good formability, creep resistance and thermal stability at room temperature.It has good fatigue resistance at room temperature and high temperature.The plates, blades and inlet boxes of civil aviation engines are all made of titanium alloy.Typical alloys used are Tc4, Tc6 (Ti-6Al-2.5Mo-2Cr-0.5Fe-0.3Si) and Tc11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si).

The period from 2020 to 2038 will be a period of great development of civil aviation in China, and the annual average growth rate of titanium in civil aircraft manufacturing will reach 6.5%.In the manufacturing of large aircraft C919, aluminum alloy accounts for 65%, about 14t/ aircraft, titanium alloy accounts for 8%, about 1.73t: the front fuselage press plate is made of TC4 alloy, the hanging joint and middle beam, the engine connection frame and the common frame are TC4 alloy forgings, and part of titanium alloy is used for the nose skin.The rear fuselage of ARJ21 regional jet is made of TC4 alloy annealed sheet, the fuselage skin is TC4 alloy, and some components of the landing gear are TC4 alloy forgings.