The history of world aviation development for more than 100 years truly interprets the phrase "one generation of materials, one generation of aircraft." Over the past 100 years, the appearance, structure and materials of aircraft have undergone earth-shaking changes. It can be said that the development of the aviation industry and the materials of the aircraft The innovative applications of, structural materials, engine materials and various component materials are inseparable.
Hay Think learned at the 2020 (6th) Shanghai International Forum on Aeronautical Materials and Manufacturing Technology held recently that as China’s materials industry is becoming stronger and China’s civil aircraft industry enters the fast lane, the scale of the future aerospace materials market Obviously, localization will also be the general trend.
The aviation composites market is large
Aviation materials are the foundation for the development of the aviation industry and involve a large amount of global import and export trade. Due to the high demand for materials by aerospace parts manufacturers, the aerospace materials market in Asia-Pacific, Europe and North America has huge potential. According to forecasts, the global aerospace materials market will reach 25.8 billion U.S. dollars by 2022, and the annual composite will be from 2017 to 2022. The growth rate was 6.9%. In addition, by 2023, the size of the composite materials market in China's aviation industry alone will reach 28.27 billion yuan.
Materials are important technical guarantees for realizing advanced aircraft with high performance, light weight, high reliability, long life, and low cost. The aircraft has the characteristics of multiple uses, diverse use environments, and harsh service environments. These are all important to the materials and manufacturing of the aircraft. Technology puts forward high demands. Based on the importance of aircraft materials, the world's aviation powers attach great importance to the development of aircraft materials. The progress and development of aviation technology promote the renewal of aviation materials. At the same time, the emergence of new materials and the advancement of manufacturing processes and physical and chemical testing technologies have provided an important material and technical basis for the design and manufacture of aviation products, thereby continuously promoting the development of the aviation industry.
Up to now, China’s domestically produced "Xinzhou" series aircraft have been delivered more than 100, ARJ21 regional airliner has delivered 39, large trunk airliner C919 is undergoing intensive test flight, domestic and foreign orders reached 815, China's civil aircraft industry has entered the fast lane of development . Composite materials have been widely used in the aerospace field. In terms of large passenger aircraft, the most advanced Boeing 787 and Airbus A350 in the world, as well as the domestic large aircraft C919 and the Sino-Russian wide-body aircraft project CR929 all use a large number of composite materials.
According to Chen Ping, Director of the Typical Structure Department and R&D Engineer of COMAC's Composite Materials Center, advanced metal materials developed at home and abroad are used in the domestic large aircraft C919, and the composite materials are mainly used in the rear fuselage section of the C919. The material consumption is about 12%; however, in the future CR929, except for the nose, the entire fuselage and wing and tail fins are planned to use composite materials, and the consumption target is more than 50%.
She believes that the use of composite materials in large passenger aircraft is expanding from secondary bearing structures such as tail fins to main bearing structures such as fuselage and wings. "At present, the maturity and production efficiency of the application of composite materials for domestic large passenger aircraft in China need to be improved. Fully automatic specialized production needs to be realized, and liquid molding technology needs to enter the production line for formal application. High performance, high efficiency, and low cost It will be the main development direction of the raw materials field in the future."
The market is increasingly demanding aviation materials
For more than 100 years, people’s requirements for airplanes have become higher and higher: passengers demand more safety and comfort, manufacturers demand lower costs and more durability, airlines demand more economical operations… In fact, these demands are related to the innovation and upgrading of aviation materials and manufacturing processes. Inseparable.
To achieve the above goals, for civil aircraft designers, it is necessary to achieve weight reduction and long-life design; for materials, light weight and high damage tolerance performance are required. In layman's terms, the aircraft must be light enough and durable enough.
Li Hongping, deputy chief designer and researcher of COMAC Shanghai Aircraft Design and Research Institute, said that although the proportion of composite materials on new aircraft is increasing, metal materials are still the main body. C919 aluminum alloy accounts for 62%, and ARJ21 accounts for 72%. %. However, the new generation of aluminum-lithium alloys has been required to be lightweight, and the market has increasingly higher requirements for aviation materials.
Combining the current status of COMAC and the R&D direction of foreign suppliers, Li Hongping predicts that the main R&D directions of metal materials in the next 5 to 10 years are: aluminum-lithium alloys suitable for applications such as fuselage panels, beams, and fuselage frames Thick plate, suitable for aluminum-lithium alloy thin plate for fuselage skin, suitable for aluminum-lithium alloy profile for long truss of skin wall panel, advanced aluminum alloy with high (medium) strength, high toughness and damage tolerance, high damage resistance Tolerance performance, ultra-high strength stainless steel, etc.
The localization of aviation materials is the general trend. As a global leader in steel technology, ZGBW Steel Technology Group has been committed to the development and application of new materials. According to Ma Tianjun, deputy chief engineer of ZGBW, titanium alloys, high-temperature alloys, and ultra-high-strength steels in ZGBW products are highly related to aviation materials. The company passed the dual vacuum smelting of superalloys in 1966, and has achieved major breakthroughs in national major equipment materials in recent years. At the same time, its development of new deformed superalloys has been accelerating, and it has also cooperated with research institutions to develop a series of high-temperature resistant and difficult-to-deformed superalloy materials. Some products have achieved engineering applications and provide more optional materials for aero engines. He hopes that in the future, more research will be conducted in areas such as special metallurgy, so that the quality of metallurgical technology will not drag the aviation industry down.
Zhang Xuejun, deputy chief engineer of the Beijing Aviation Materials Research Institute of China Aviation Development, said that for aircraft and engines, materials require light weight, high strength, high temperature resistance, low defects and high stability in structure. This is a must-solved problem for aviation material additive manufacturing.
Additive Manufacturing (AM) is commonly known as 3D printing, which combines computer-aided design, material processing and molding technology. Based on digital model files, special metal materials, non-metal materials and medical biological materials are combined through software and numerical control systems. It is a manufacturing technology that builds solid objects layer by layer according to extrusion, sintering, melting, light curing, spraying, etc. Different from the traditional processing mode of cutting and assembling raw materials, this is a "bottom-up" manufacturing method through material accumulation. This makes it possible to manufacture complex structural parts that were restricted by traditional manufacturing methods in the past.
In order to realize the reliable application of additive manufacturing, Zhang Xuejun proposed solutions. One is to ensure the reliability of materials and structures used in aircraft and engines by studying the entire process performance and key technologies of aircraft and engines in terms of organization, surface and structure; Second, we must pay attention to solving basic problems and improve technological maturity; third, we must formulate industry standards for the entire process.
Establish a standard system for China's civil aircraft materials industry
Improving the supply of aviation materials is an important basic support for the development of advanced manufacturing and the building of a manufacturing power. In recent years, the state has successively issued a series of major policies in the field of new materials, which have pointed out the direction and provided development space for comprehensively promoting the adjustment of the national new material industry structure and the transformation and upgrading of the manufacturing industry.
At present, with the joint efforts of all parties, China has basically formed a relatively complete aviation material development technology system and mass production capacity, and has the ability to supply key materials for major aviation equipment. However, the proportion of installed capacity of domestic materials and the quality control capabilities of material manufacturers still lag far behind the international advanced level.
In order to enhance the international competitiveness of civil aircraft materials and improve independent innovation capabilities, COMAC has also been committed to relying on large passenger aircraft projects to improve the level of research and application of new domestic civil aircraft materials, traction by model requirements, and mastering key core technologies. The goal is to promote the development of the civil aircraft material industry; at the same time, with the airworthiness requirements as the guide, establish a civil aircraft material development and certification system that meets the airworthiness certification requirements, and explore the establishment of a Chinese civil aircraft material industry standard system.
To this end, COMAC established the Composite Materials Center in October 2018, which is mainly responsible for the typical structure of composite materials and the entire process management of related products from pre-research, design, process, manufacturing, and maintenance, as well as quality, schedule, cost, and airworthiness. At the same time, he is responsible for the construction of COMAC's composite material technology system and the preparation of standards and specifications, as well as the output and control of the professional technology of composite material product suppliers.