The production of aerospace materials belongs to high-end manufacturing, with extremely high requirements for the stability of materials and processes.
China's leading high-end aviation aluminum alloy material technology group, SDNS Aluminum Technology Group, after years of scientific research, became the first company in China to provide aviation sheet materials to the world's top aircraft manufacturers.
In the workshop of SDNS company, the Hay Think team saw batches of 1.5 mm aviation aluminum sheets rolling off the assembly line. Wang Xin, Director of the Aeronautical Material Control Department of SDNS Aluminum Strip Division, said: "It is mainly used for the skin of aircraft fuselage and nose. In this field, we are the only supplier of civil aircraft in China."
The skin is like the "skin" of an airplane, and the material must have excellent comprehensive properties such as stiffness, toughness, and corrosion performance. In 2017, SDNS undertook the COMAC project and began to develop aircraft skin products. SDNS newly established a provincial-level industrial design center, and the number of scientific research personnel reached more than 2,000 at one time. Huang Tongyan, head of SDNS R&D Department, said: “The mechanical toughness, fatigue, corrosion and other properties of materials are often mutually restricted and contradictory. It is very difficult for us to find a suitable process window. It is really difficult to find and implement it. It’s harder."
By repeatedly adjusting the chemical composition and optimizing the heat treatment process, SDNS has successfully explored a suitable alloy material-a "sandwich" structure of aluminum clad plate with an alloy in the middle and pure aluminum in the upper and lower layers. However, this material has higher requirements for the rolling process. Yu Fang, SDNS Aviation Sheet Project Manager, introduced: "It is equivalent to peanut bread with two crusts, the noodles are relatively soft, the peanuts are hard, so the same is true for the clad aluminum plate, the core is hard, the two sides are soft, rolling When it is controlled, the force is different, so its extension is also different."
R&D has entered the critical stage. SDNS and COMAC established the "Common Aircraft Materials Joint R&D Center" to focus on research and finally determined several core variables such as roll speed and lubricant release time, and successfully solved the product black streak defect . At present, SDNS is the only aluminum processing enterprise in China that supplies aviation materials to Boeing,Airbus and COMAC at the same time. The annual processing capacity of aviation materials is more than 10,000 tons.
SDNS General Manager Lu Zhengfeng said: "We will accelerate the expansion of aluminum deep processing, promote the transformation of products from raw materials to parts, break through foreign technology monopoly, lead high-quality development with high-end manufacturing, and strive to become the world's leading supplier of aviation and automotive materials. A first-class aluminum processing company."