The invention patent of a high-strength, high-toughness, and low-quenching-sensitive aluminum alloy for large aircrafts "an aluminum alloy product suitable for the manufacture of structural parts and a preparation method" has obtained invention patent authorization in the United States and Canada. So far, on the basis of the publication of the international PCT organization and the European Patent Office's authorization for the above-mentioned new aluminum alloy invention patents, the number of patent authorized countries has increased to 12, all of which are the major aircraft and aviation aluminum alloy manufacturing countries in the world, including The United States, France, the United Kingdom, Canada, Germany, Norway, Australia, Italy, Spain, Austria, Japan and China are the first aviation aluminum alloy materials in China that have obtained a wide range of international invention patents.
Aviation aluminum alloy is the backbone material for the manufacture of aircraft and spacecraft. With the continuous improvement of the requirements for flight performance, payload, fuel consumption, service life, and safety and reliability of contemporary aircraft design and manufacturing, the overall performance and reduction effect of aluminum alloy structures have also become higher and higher. Integral aluminum alloy structural parts are processed by CNC milling of large-sized aluminum alloy materials, instead of the traditional composite structural parts assembled from multiple aluminum alloy parts, which can not only achieve significant weight reduction of the structural parts, but also improve the reliability of the service process. And it can reduce the assembly process of the aircraft and reduce the manufacturing cost. This advanced design and manufacturing method puts very strict requirements on aluminum alloy materials: the maximum thickness of aluminum alloy forgings or pre-stretched plates often needs to reach more than 150mm, and the comprehensive performance of parts with different thicknesses is highly uniform, while also having excellent The strength-plasticity-fracture toughness-fatigue resistance-stress corrosion resistance and spalling corrosion resistance match.
Since the launch of the National Large Aircraft Major Scientific and Technological Project in 2006, in the design of China's transport -20 large transport aircraft and C919 large passenger aircraft, some large key structural materials must be selected from high-strength, high-toughness, and low-quenching-sensitive aluminum alloy large-size materials. During the "Eleventh Five-Year Plan" period, supported by the National Natural Science Foundation of China, 973, 863, and International Cooperation Programs, Youyan Technology Group Co., Ltd., a non-ferrous metal material affiliated to the company (formerly Beijing Nonferrous Metal Research Institute) The aluminum alloy team led by Professor Xiong Baiqing from the State Key Laboratory of Manufacturing and Processing, after in-depth research, put forward the composition design of domestic high-strength high-toughness-low quenching sensitivity aluminum alloys and the microstructure control guidelines during the manufacturing process, forming a complete experiment Laboratory technology prototype, applied for a new alloy invention patent, which covers more than 40 claims such as new alloy composition design, full-process manufacturing and processing technology, and provides a solid technical and intellectual property protection for the development of new alloys. During the "Twelfth Five-Year Plan" period, with the support of the major large-scale scientific and technological special materials research and development project of the country's large aircraft, it cooperated closely with ZLXN Aluminum Corporation, Beijing Aeronautical Materials Research Institute and other units to carry out industrial trial production, and successively achieved The Yun-20 large-scale transport aircraft was developed and designed with more than ten specifications of super-large thickness forgings. The overall performance is equivalent to that of the US 7085 alloy product, and some key performances have been surpassed. Since the "Thirteenth Five-Year Plan", Southwest Aluminum has supplied nearly 1,000 tons to AVIC Corporation. At the same time, the multi-specification super-thickness pre-stretched board developed for COMAC has completed the project transition review. The qualification certification of aviation qualified suppliers is progressing smoothly.
In the next step, Yuyan Group will further deepen research with production units, continuously improve the industrial batch production management system, accelerate the certification of civil aircraft airworthy suppliers of a series of specifications, and continue to expand domestic high-strength high-toughness-low quenching sensitivity aluminum alloys. The application range of materials in new aircraft and space vehicles supports the development of China's aerospace industry.