C919 "skin" secret: interpretation of domestic large aircraft material selection-Nanjing New Nuclear Composites Co., Ltd.

Language
- ENGLISH
- CHINESE

C919 "skin" secret: interpretation of domestic large aircraft material selection

Release time:

2018-09-14

"It can be said that the C919 is currently the most advanced metal materials, and all the aluminum alloys used are the best in the world." On November 2, it was learned that C919 was officially offline. Zhang Xinming, a professor at the School of Materials Science and Engineering of Central South University, who twice served as the chief scientist of the National 973 Project for High-performance Aluminum Alloy Materials, told the reporter of Science and Technology Daily. "A generation of materials, a generation of aircraft." Assistant to Professor Zhang Xinming, Deng Yunlai, an important member of the national 973 project "Basic Research on Aviation High-performance Aluminum Alloy Materials" and a professor at the School of Materials of Central South University, further explained, "As the first independent student in my country

"A generation of materials, a generation of aircraft." Assistant to Professor Zhang Xinming, Deng Yunlai, an important member of the national 973 project "Basic Research on Aviation High-performance Aluminum Alloy Materials" and a professor at the School of Materials of Central South University, further explained, "As the first large passenger aircraft independently produced in my country, the choice of materials directly Determines many of its characteristics."

According to Xinhua News Agency, the C919 "shell" all by China's independent design, manufacturing.

"The casing is called the body professionally, and the aluminum alloy material accounts for about 70% of the total weight of the material." Deng Yunlai introduced, "In order to reduce its own weight and fuel consumption, the weight of the aircraft will be accurate to the gram, and the C919 achieves the strategic goal of 5%-10% lighter than similar models such as the B737 and A320, mainly thanks to the addition of lithium in aluminum alloys. Although lithium only accounts for about 2% of the weight of the aluminum alloy, it can reduce its weight by more than 5% compared to regular aluminum alloys under the same load."

Traditionally, many foreign large aircraft models have used a large number of regular high-performance aluminum alloy materials, such as 7X49, 7055, 7085, 2X24 and so on. "This material is also in line with the characteristics of high strength, high toughness, fatigue resistance, damage resistance, corrosion resistance and so on, but its own weight will be heavier than C919." Deng Yunlai said.

Published reports show that the use of composite materials accounts for about 12% of the weight of the C919 aircraft structure?

"The composite materials used in aircraft are mainly carbon fiber reinforced resin matrix composite materials. They have the characteristics of high corrosion resistance and light weight. They are indeed superior to ordinary metal materials in these properties." Deng Yunlai said.

However, there is no such thing as a free lunch.

Deng Yunlai smiled and said, "Usually, the price of composite materials is about dozens of times that of regular aluminum alloy materials, and even our already expensive aluminum-lithium alloy materials are much lower than composite materials. Therefore, our C919 is only about 1/2 of the price of a Boeing 737."

"Aluminum alloy materials need not only high strength, but also high toughness, as well as fatigue resistance, damage resistance and corrosion resistance, which is a very complex contradiction and unity," Zhang Xinming said. At present, domestic research on metal materials for large aircraft has obtained more than 200 patents, about half of which are owned by Central South University. "For example, strength, toughness and corrosion resistance are often contradictory. If we want to achieve them at the same time and keep them stable, we must continue to study them. This is the charm of metal materials."

In response to many criticisms about the "autonomy" of large aircraft materials, Zhang Xinming said: "The characteristics of large aircraft, especially large civil aircraft, determine that they have very high performance requirements for materials and must be very stable. In this regard, there is a set of very strict standards. To ensure. In recent years, the country has attached great importance to the research of large aircraft and has made a lot of important progress in the field of metal materials, but after all, it is only ten years for us to organize basic research on aluminum alloy materials for large aircraft on a large scale. Compared with some countries with early development, there is still a big gap in basic, engineering research and industrial batch production technology accumulation, and it is necessary to increase the basic and applied research of aluminum alloy materials."

安安