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Research progress and trends of new materials in China's aerospace industry

In recent years, while the aviation industry at home and abroad continues to pay attention to the safety of aircraft and engines, it has also increasingly focused on issues such as resource conservation, cost reduction, and environmental protection. Against this backdrop, the green aviation industry has made certain progress. Green aviation covers the entire development and use process of aircraft design, manufacturing, use, maintenance, retirement, and recycling, involving technical fields such as green materials, green manufacturing, and green maintenance.
The so-called green materials refer to the full cycle of material design, raw material selection, processing and manufacturing, packaging and transportation, use, recycling, and reuse, in order to achieve resource utilization and minimize usage costs and environmental impact as much as possible. China has begun to vigorously develop new material technology, and various new material technologies have made continuous breakthroughs. The research on aviation new materials has also achieved gratifying results. Looking ahead to the future, aviation new materials will develop towards multi-purpose, high-performance, new processes, low cost, and new concepts. With the improvement of China's independent research and development level in the field of aviation new materials, we need to start from material design, preparation process, material development, and recycling and reuse, improve the green technology level of aviation materials, and jointly create a beautiful future of green aviation.
The necessity of developing the green aviation industry
2021 is the beginning year of the 14th Five Year Plan, and the new materials sector, as the core position of the entire military industry chain, is expected to usher in significant development space. The 20th century was a century of rapid development of modern science and technology, and one of its important symbols was the brilliant achievements of humanity in the field of aerospace. In the 21st century, aerospace has shown broader development prospects, with more frequent high-level or ultra high level aerospace activities. The tremendous achievements in the aerospace industry are inseparable from the development and breakthroughs in aerospace material technology. Materials are the foundation and precursor of modern high-tech and industry, and to a large extent, a prerequisite for breakthroughs in high-tech. The development of aerospace materials provides strong support and assurance for aerospace technology; On the other hand, the development demand of aerospace technology greatly leads and promotes the development of aerospace materials. It can be said that the advancement of materials plays a crucial supporting role in the upgrading and replacement of aircraft.
Aviation materials are not only the material guarantee for the development and production of aviation products, but also the technical foundation for the upgrading of aviation products. Materials play an extremely important role in the development of the aviation industry and aviation products. In the 21st century, aviation materials are developing towards high performance, high functionality, multifunctionality, integrated structure and function, composite, intelligent, low-cost, and environmentally compatible directions.
In 2020, General Secretary Xi Jinping profoundly pointed out that "humanity needs a self revolution to accelerate the formation of green development and lifestyle, build ecological civilization and a beautiful earth." Former Premier Li Keqiang proposed in the 2022 government work report to continuously improve the ecological environment, promote green and low-carbon development, strengthen pollution control and ecological protection and restoration, handle the relationship between development and emission reduction, and promote harmonious coexistence between humans and nature. In recent years, while the aviation industry at home and abroad continues to pay attention to aircraft safety, it has also increasingly focused on issues such as resource conservation, cost reduction, and environmental protection. Against this backdrop, green aviation has made certain progress. Aircraft are developing towards greater safety, reliability, lightweight, toughness, and environmental friendliness, which has raised increasingly high requirements for materials and promoted upgrades in flight speed, reliability, low cost, efficiency, and comfort. Under the new industrial situation, the development of high-end aviation green materials and their preparation and processing technologies is of great significance in supporting the sustainable development of China's aviation industry. In summary, driven by the rapid development of modern industries worldwide, the green development of aviation materials is an inevitable trend and an urgent requirement for economic development.
02. Research progress of aviation new materials
Aircraft materials to some extent determine the manufacturing cost of aircraft body structure. Due to the early introduction of aviation equipment in China, the material selection mainly used foreign material systems. In recent years, China has vigorously developed new material technologies, and various new material technologies have made continuous breakthroughs. The research on aviation new materials has also achieved gratifying results. However, there is still a significant gap between the overall level of the aviation new materials industry and the international advanced level.
（1） Titanium alloy: a "* metal" with excellent properties
Titanium metal has the characteristics of low specific gravity and high specific strength, and its alloy is of great significance in improving the thrust to weight ratio of aircraft in the aerospace field, and has been widely used in recent years. In addition to military and aerospace industries, titanium alloys are also widely used in chemical, metallurgical, medical, sports and leisure industries.
Development status of titanium alloy materials for foreign aviation
1) High temperature titanium alloy: High temperature titanium alloy is mainly used in structural frame components such as aircraft flap slides, bearing housings, brackets, engine hoods, compressor discs and blades, and casings. These components require materials to have high specific strength, fatigue strength, creep resistance, and structural stability under high temperature conditions of 300-600 ℃. At present, the high-temperature titanium alloys that represent the international advanced level mainly include Ti-6242S from the United States Ti-1100， IMI834 from the UK, BT36 from Russia, etc.
2) High strength titanium alloy: High strength titanium alloy usually refers to titanium alloy with a tensile strength greater than 1000MPa, mainly used to replace high-strength structural steel commonly used in aircraft structures, and can achieve a weight reduction of 10%. At present, the high-strength titanium alloys used in aircraft are mainly β - type titanium alloys, with representative ones including Ti-1023, BT22, Ti-153, β -21S, etc.
3) Flame retardant titanium alloy: Currently, typical flame retardant titanium alloys include Alloy C from the United States and BTT-1 from Russia. The Alloy C (Ti-35V-15Cr) alloy developed in the United States is a β - type titanium alloy with excellent high-temperature strength and oxidation resistance. It has been applied to the high-pressure compressor casing, guide vanes, and vectoring nozzle of the Fl19 engine. The Ti Cu Al BTT-1 flame retardant titanium alloy developed by Russia has good hot workability and has been used in engine compressor casings and blades.
Development status of titanium alloy materials for domestic aviation
1) High temperature titanium alloy: Ti-60 alloy is a 600 ℃ high-temperature titanium alloy independently developed by China. This alloy is based on TAl ₂ (Ti-55) alloy with appropriate amounts of Al, Sn, Si elements added, thereby further improving the thermal stability, high-temperature creep performance, and high-temperature oxidation resistance of the alloy.
2) High strength structural titanium alloys: China independently developed a batch of high-strength structural titanium alloys in the 1970s and 1990s. The strength of these titanium alloys can reach a level of 1100-1300MPa. There are two representative β - titanium alloys developed in the early 21st century: ① Ti-B18, a nearly β - titanium alloy with a tensile strength of up to 1150-1350MPa; ② The metastable β - titanium alloy Ti-B20 has a tensile strength of up to 1200-1600MPa.
3) Flame retardant titanium alloys: Over the years, China has conducted in-depth research on flame retardant titanium alloys. Referring to AlloyC alloy, three series of flame retardant titanium alloys, Ti-V-Cr Al, Ti-Mo-Cr-Al, and Ti-Mo-V-Cr-Al, have been designed, and the anti combustion mechanism has been studied using computer simulation methods. In addition, after systematically analyzing the flame retardant titanium alloys of different systems in the United States, United Kingdom, and Russia, TF1 (Ti-V-Cr-C system) and TF2 (Ti Cu system) flame retardant titanium alloys were designed respectively. Ti-40 (Ti-V-Cr-Si) alloy is a self-developed β - type flame-retardant titanium alloy in China. Compared with conventional titanium alloys, Ti-40 alloy has excellent flame-retardant and mechanical properties. At present, the research on this alloy has developed from laboratory scale to semi industrial scale, and can now prepare Ti40 ton grade ingots, large-sized bars, and ring forgings.
Due to the late start of the domestic aviation manufacturing industry, the usage of titanium and titanium alloy materials in China's aviation field is not large. The proportion of titanium materials used in the aviation field is less than 20%, far below the international average of about 50%. Compared with developed countries in the titanium industry, there is still a considerable gap. Firstly, high-end titanium alloy products are still mainly copied, with low material development level and narrow application scope. The development of high comprehensive performance and low-cost titanium alloys is mostly in the laboratory stage; Secondly, the metallurgical quality is unstable, with few varieties and incomplete specifications; Thirdly, the research progress of related supporting technologies is slow, and the independently developed titanium alloy material system needs to be improved.
（2） High temperature alloys: focus on military engine demand
High temperature alloys, born for high temperatures
Traditional steel will soften above 300 degrees Celsius and cannot adapt to high temperature environments. In order to pursue higher energy conversion efficiency, the working temperature required in the field of thermal power is increasing. High temperature alloys were born from this and can work stably in high temperature environments above 600 degrees Celsius, with continuous technological advancements.
High temperature alloys are divided into iron-based high-temperature alloys and nickel based high-temperature alloys according to their main elements. According to Zhiyan Consulting, in 2018, nickel based high-temperature alloys accounted for 80% of the production, iron-based high-temperature alloys accounted for 14.3%, and cobalt based high-temperature alloys accounted for 5.7% based on product processes.
High temperature alloys are key materials for aircraft engines. High temperature alloys have been used in aviation engines since their inception and are important materials for manufacturing aerospace engines. The performance level of the engine largely depends on the performance level of the high-temperature alloy material. In modern aviation engines, the amount of high-temperature alloy materials accounts for 40% to 60% of the total weight of the engine, mainly used for the four hot end components: combustion chamber, guide vanes, turbine blades, and turbine discs. In addition, they are also used for components such as the casing, rings, afterburner, and exhaust nozzle.
The high-temperature alloy industry in our country is currently in a growth stage, and the future development space of industrial chain enterprises is vast. The number of high-temperature alloy production enterprises in China is limited, and the production level lags behind that of countries such as the United States and Russia. However, in recent years, there has been a significant increase in production capacity and output value. Several high-temperature alloy production projects of companies such as Lianshi Aviation and Western Superconductor are currently under construction and operation.
The performance of high-temperature alloys for aircraft engines continues to develop
1) Iron based high-temperature alloys: a major feature of China's high-temperature alloy system.
Due to the scarcity of nickel and cobalt resources in our country, the research, production, and application of iron-based high-temperature alloys became a magnificent scenery in the 1960s and 1970s.
Iron based high-temperature alloys are used at lower temperatures (600~850 ℃) and are generally used in engine parts with lower operating temperatures, such as turbine discs, casings, and shafts. However, iron-based high-temperature alloys have good mechanical properties at medium temperatures, comparable to or better than similar nickel based alloys. In addition, they are inexpensive and easily deformed during hot working. Therefore, iron-based alloys are still widely used as materials for turbine disks and blades in the medium temperature field.
2) Nickel based high-temperature alloys: deformation/casting/upgrading of new alloys generation by generation.
Nickel based high-temperature alloys generally work under certain stress conditions above 600 ℃. They not only have good high-temperature oxidation resistance and corrosion resistance, but also have high high-temperature strength, creep strength, endurance strength, and good fatigue resistance. Mainly used for structural components working under high temperature conditions in the aerospace industry, such as working blades, turbine disks, combustion chambers, etc. of aircraft engines.
Nickel based high-temperature alloys can be divided into variable alloys, cast high-temperature alloys, and new high-temperature alloys according to manufacturing processes. Nickel based cast high-temperature alloys are mainly used for turbine guide vanes in engines, with a working temperature of over 1100 ° C. They can also be used for turbine blades, which can withstand temperatures 50-100 ° C lower than the corresponding guide vanes.
As the working temperature of heat-resistant alloys increases, the number of strengthening elements in the alloy also increases, and the composition becomes more complex, resulting in some alloys being used only in the as cast state and unable to undergo hot working deformation. Moreover, the increase in alloying elements leads to severe compositional segregation in nickel based alloys after solidification, resulting in uneven microstructure and properties. The use of powder metallurgy technology to produce high-temperature alloys can solve the above problems. Due to the small particle size of the powder, the cooling rate during powder production is fast, eliminating segregation and improving hot workability. The alloy that could only be cast is transformed into a deformable high-temperature alloy that can be hot worked, resulting in improved yield strength and fatigue performance. Powder high-temperature alloys provide a new way to produce higher strength alloys. Powder high-temperature alloys are mainly used to manufacture turbine discs for high thrust ratio advanced aircraft engines, as well as high-temperature hot end components such as compressor discs, turbine shafts, and turbine baffles for advanced aircraft engines.
3) Cobalt based high-temperature alloys have broad prospects in special fields such as corrosion resistance.
The oxidation resistance of cobalt based high-temperature alloys is poor, but their resistance to thermal corrosion is better than that of nickel; Cobalt based high-temperature alloys have stronger high-temperature strength, thermal corrosion resistance, thermal fatigue resistance, and creep resistance than nickel based high-temperature alloys, and are suitable for manufacturing gas turbine guide vanes, nozzles, etc.
Due to resource limitations, China has currently developed cobalt based alloys such as K40, GH188, and L605, which have limited applications. After 2001, General Electric's research on cobalt based high-temperature alloys mainly focused on using cobalt based alloys as substrate materials for preparing gas turbines, and preparing coatings such as thermal barrier coatings on the alloy surface to improve corrosion resistance.
Due to material limitations, cobalt has limited reserves on Earth and is relatively expensive. At present, the popularity of cobalt based research has declined, and many scientific studies are still in the theoretical stage of digital modeling experiments.
One generation of military aircraft and one generation of alloys, high-temperature alloys for engines or entering a period of rapid mass production
The engine's temperature requirements are constantly increasing. A high thrust to weight ratio requires higher nozzle temperatures and material support at higher operating temperatures. In the development process of high-temperature alloys in the world, engine blade and disk materials have gone through four stages: deformation, casting, orientation, and single crystal. Adapt to gradually increasing the temperature from 600 ° C to above 1100 ° C.
The replacement of military aircraft is accompanied by the upgrade of high-temperature alloys* The core material of the turbojet engine is deformed high-temperature alloy, with a working temperature of 650 ° C. By the fourth generation turbofan engine, the working temperature of the core material has reached 1200 ° C, using single crystal high-temperature alloy. The replacement of military aircraft throughout history has been accompanied by the upgrade of engine core materials - high-temperature alloys. The upgrade of high-temperature alloys requires support from research and development. Driven by the development needs of the aviation industry, China has successively developed deformation, casting, equiaxed crystal, directional solidification columnar crystal, and single crystal alloy systems for high-temperature alloys. The successive emergence of the above-mentioned high-temperature alloys has continuously promoted the development of the aviation industry. According to research data released by Forward Industry Research Institute, engines account for 25% of military aircraft costs, material costs account for 50% of engine costs, and high-temperature alloys account for about 35% of material costs.
（3） Carbon fiber: high technological barriers in the entire manufacturing process
Aerospace core materials with high technological barriers
Carbon fiber has superior properties such as high strength, high specific modulus (10 times stronger than steel and only half the weight of aluminum), light weight, corrosion resistance, fatigue resistance, low thermal expansion coefficient, and high and low temperature resistance. It is an important basic material for military and civilian use, applied in fields such as aerospace, sports, automobiles, buildings, and structural reinforcement. Compared to traditional metal materials, resin based carbon fiber has a higher modulus than traditional industrial materials such as titanium alloys, and its strength can reach the level of high-strength steel through design, significantly higher than titanium alloys. Its advantages in both performance and lightweight are very obvious. However, the cost of carbon fiber is relatively high. Although it has partially replaced traditional materials in high-precision fields such as aerospace, traditional industries with relatively low mechanical performance requirements place more emphasis on economic benefits, and traditional materials remain the main force.
Modern carbon fiber materials originated in military use and are currently an important application field in aerospace. Modern carbon fiber is an inorganic polymer fiber with a carbon content of over 90%, which has good flexibility, high strength in the longitudinal direction, and excellent tensile strength. It belongs to the new generation of reinforcing fibers, and carbon fiber has stable chemical properties, strong high-temperature resistance, and is not easily corroded. It is an ideal material for large-scale integrated structures. Compared with conventional materials, carbon fiber composite materials can reduce the weight of aircraft and have the ability to overcome the disadvantages of metal materials such as fatigue and corrosion. The main military carbon fiber industry chain enterprises in China include AVIC High Tech, Guangwei Composite Materials, Zhongjian Technology, etc. Among them, AVIC High Tech is located downstream and mainly produces aviation composite products; Guangwei Composite Materials has achieved a full industry chain layout and is a leader in the carbon fiber industry; Zhongjian Technology's layout is relatively upstream, and its product technology content is relatively higher.
The development of carbon fiber technology has undergone three generations of changes, and achieving high tensile strength and elastic modulus at the same time is currently a technical difficulty in the development process of carbon fiber. In recent years, Japan and the United States have made technological breakthroughs in third-generation carbon fiber through two different technological paths, and are expected to achieve industrial production in the next 5-10 years, which is of great significance for improving the combat capabilities of fighter jets and weapons. Dongli utilizes traditional PAN solution spinning technology to significantly improve the strength and elastic modulus of carbon fibers. By finely controlling the carbonization process, the microstructure of carbon fibers is improved at the nanoscale, and the orientation, size, and defects of graphite microcrystals in the carbonized fibers are controlled. Taking the current advanced carbon fiber product T1100G from Dongli as an example, the tensile strength and elastic modulus of T1100G are 6.6 GPa and 324 GPa, respectively, which are 12% and 10% higher than T800, respectively, and are entering the industrialization stage. Georgia Institute of Technology in the United States starts with the preparation process of precursor, uses the innovative PAN based carbon fiber gel spinning technology to connect polymers together through gel to generate strong chain forces and the directionality of microcrystalline orientation, so as to ensure high strength under the condition of large microcrystalline size required for high elastic modulus, thus improving the tensile strength of carbon fiber to 5.5~5.8GPa, and the tensile elastic modulus to 354~375GPa.
The military demand space is vast, and the downstream market is mainly dominated by CFRP
Carbon fiber composite material refers to a composite material with at least one reinforcing material being carbon fiber, among which the most common is resin based carbon fiber composite material (CFRP). Due to the significant advantages of mechanical properties such as specific strength and elastic modulus, as well as fatigue resistance and stability compared to traditional materials, CFRP has formed a competitive substitution situation for metal materials, especially lightweight metal materials, in many fields. CFRP has a wide range of application scenarios and has taken the lead in forming large-scale markets in the aerospace and sports leisure fields. With the continuous decrease in manufacturing costs of carbon fiber and its composite materials since the 21st century, its application proportion in automotive manufacturing, wind power generation and other fields is constantly increasing.
Carbon carbon composite materials: a new type of brake material with bright prospects in the military market
Carbon/carbon composite materials are composite materials reinforced with carbon fibers and based on chemical vapor deposition carbon or resin carbon, mainly used as brake discs. Brake discs are brake products with friction material design and preparation technology as the core, used for braking of aircraft, tanks, armored vehicles, and high-speed trains.
In the "Severe Landing Stop" experiment, considering the damage of other braking systems, the aircraft wheel brakes can absorb over 300 megajoules of energy and quickly reach temperatures above 1000 degrees Celsius in a short period of time. Therefore, the aircraft has strict requirements for the high temperature resistance and stability of brake disc materials, as well as reducing deformation. Compared with steel brake discs, the outstanding advantages of carbon brake discs are:
1) Reduced the weight of the brake system
2) Improved the service life of brake discs
3) High working temperature
4) Brake smoothly
Due to a series of advantages such as low density, high temperature resistance, corrosion resistance, excellent friction and wear performance, good thermal vibration resistance, and low risk of sudden catastrophic damage, carbon/carbon composite materials have become the * braking material for aviation braking devices. Modern high-performance civil aircraft, such as Boeing 747, Boeing 757, Boeing 767, Airbus series, McDonnell Douglas series, etc., all use carbon/carbon composite brake material brake devices. With the continuous development of China's economy and the deepening of economic globalization, the entire aviation industry is showing a rapid development trend. The continuous expansion of the number and scale of domestic operating fleets has brought huge opportunities for the development of civil aviation product business. As consumables, aircraft brake discs need to be replaced every time they wear to the standard, and the market demand is high. Currently, they mainly rely on imports.
In order to further improve the mechanical performance of carbon brake discs and enhance the safety of brake materials and aircraft, domestic companies represented by Beimo High tech and Xi'an Braking have adopted a combination of integral needle felt and chemical vapor deposition technology to prepare carbon brake discs, ultimately achieving the localization of carbon brake discs.
The development trend of aviation new materials
（1） The development trend of titanium and titanium alloy materials
Titanium alloy has become an ideal structural material for the aviation industry due to its excellent performance characteristics. From the current development trend of materials used in aviation parts in developed countries, the aviation industry is the application field of titanium alloys. Titanium alloy materials with high strength and low density will still be one of the main materials in the aviation field for a long time. The rapid development of aviation technology has put forward higher requirements for the new generation of aviation aircraft: ultra-high speed, high altitude, long endurance, ultra long range, etc. In addition, in order to improve the reliability of aircraft, the amount of high-performance materials such as titanium alloys is increasing. Therefore, aviation titanium alloys will develop towards high performance and low cost. The current research hotspots mainly focus on the development of new titanium alloy materials, the development and application of welding and processing forming processes, as well as additive manufacturing technology and low-cost manufacturing technology for complex components.
Research and development of low-cost aviation titanium alloys
The aviation industry places greater emphasis on balancing performance and cost in its material requirements. Low cost will run through the entire lifecycle of products, including material selection, structural design, manufacturing processes, testing and evaluation, and maintenance. Reducing the cost of titanium alloys has become an inevitable trend in the industry's development. Firstly, we need to break away from the long-term dependence on imported aviation key materials and establish our own titanium alloy system, laying the foundation for achieving low-cost manufacturing fundamentally. Secondly, developing new materials and processes to reduce costs, replacing precious metal elements such as Nb, Mo, and V with lower priced elements, and vigorously developing new technologies for near net forming.
Research and development of high-performance aviation titanium alloys
At present, it is difficult for high-temperature titanium alloys to exceed 600 ℃ for long-term use. Research on aviation titanium alloys above 600 ℃ is still in the experimental and pilot stages, and there is still a long way to go before large-scale development and application. In addition, the batch stability research and application of flame-retardant titanium alloys, high-strength, high toughness, and damage tolerant titanium alloys have become a focus of attention for many scholars. In the future, research on high-performance aviation titanium alloys will tend to delve deeper into existing alloys and develop new grades of alloys.
Application of additive manufacturing in aviation titanium alloys
In recent years, with the development and application of additive manufacturing technology, laser additive manufacturing of titanium alloys has overcome the shortcomings of traditional technology, such as difficulty in producing complex titanium alloy components and high resistance to cold processing deformation of titanium alloys. It provides a new technological approach for the manufacturing of large integral structural components, and has mechanical properties equivalent to forgings. Titanium alloy additive manufacturing technology will become a new way for the processing and forming of aviation titanium alloys.
Recycling and Reuse of Titanium Alloy Materials
The recycling and reuse of general alloys such as pure titanium and TC4 (Ti-6Al-4V) have achieved certain results both domestically and internationally. However, in the field of "high-end" applications, China still lags behind developed countries in Europe and America. Therefore, developing China's titanium alloy material recycling and reuse technology, establishing standards and specifications for recycling and reuse materials, and researching and developing high-end equipment and technologies for recycling and reuse have become one of the directions for developing green aviation titanium alloy materials.
（2） The development trend of new composite materials
Composite materials have far superior performance and functionality compared to traditional metal materials, and various composite materials are becoming increasingly widely used in the aviation industry. The new model requirements provide new impetus and opportunities for the development of advanced composite materials, and the research and development of advanced composite materials is moving towards higher comprehensive performance, process performance, low cost, and green environmental protection. Among them, green composite materials, as a new member of the composite material family, have received increasing attention. The green development of high-performance composite materials is essentially the use of green materials and the green manufacturing of materials.
Development of Recycling and Reuse Technology for Carbon Fiber Reinforced Polymer (CFRP)
According to statistics, the global production capacity of CFRP has exceeded 3000t/a, and aircraft using CFRP as raw material will generate about 20t of carbon fiber waste when retired. Therefore, the aviation industry has become the main source of carbon fiber waste. In recent years, countries such as the UK, Germany, and Japan have been committed to developing recycling technologies for carbon fiber reinforced plastic (CFRP) and have achieved certain results.
Development technology of new composite materials
The thermosetting resin of aviation composite materials is mainly composed of epoxy resin, but the cured product of epoxy resin is difficult to degrade, which brings serious environmental pollution problems. Therefore, research and development of degradable epoxy resin has begun in recent years. Since the 1990s, various countries have successively developed a series of high-performance thermoplastic resins, such as polyphenylene sulfide series, polyether ketone series, etc. These degradable thermoplastic resin composites have greatly improved in comprehensive mechanical properties, corrosion resistance, and toughness, and have the characteristics of secondary and multiple molding. They can also be recycled and reused, and are widely used in the main load-bearing structures of aircraft. However, there are still several issues in the development of new thermoplastic composite materials: firstly, the high cost of the matrix; The second issue is the difficulty and quality stability of automated forming technology for large and complex components, and the high melting point increases the technical difficulty of preparation and forming processing; The third is the development of new resin composite materials with the goal of improving material strength, stiffness, dimensional stability, and high temperature resistance.
Low cost and green composite material preparation technology
Carbon fiber is the main reinforcement of advanced composite materials. Currently, the carbon fiber used in China mainly relies on imports and is independently developed and produced, which will further reduce the cost of advanced composite materials. The low-cost and green preparation technology of carbon fiber composite materials mainly includes: (1) developing new carbon fiber precursors (raw fibers), (2) developing various new technologies and processes.
In summary, driven by the rapid development of modern industry, the green development of aviation materials is an inevitable trend and an urgent requirement for economic development. Looking ahead to the future, aviation new materials will develop towards multi-purpose, high-performance, new processes, low cost, and new concepts. With the improvement of China's independent research and development level in the field of aviation new materials, we need to start from material design, preparation process and technology, material development, and recycling technology, etc., to improve the level of material green technology, so as to drive the continuous development and breakthrough of materials, and jointly create a beautiful future of green aviation.

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