[China Aluminum Industry Network] 1 aluminum matrix composite materials and preparation methods According to different reinforcements, aluminum matrix composites are divided into fiber-reinforced and grain-reinforced, whisker-reinforced aluminum matrix composites (equiaxed grains with a diameter between 0.5 and 100 μm). The commonly used reinforcing particles mainly include SiC, Si3N4, Al2O3, TiC, TiB2, A1N, B4C and graphite particles or metal particles. Several common aluminum-based composite materials are prepared by powder metallurgy, pressure infiltration, reaction self-generation, high-energy high-speed consolidation, semi-solid mixing, spray deposition, friction stir processing, and ball milling. Carbon nanotubes reinforced aluminum matrix composites. TiB2/A1 composites are prepared in many ways, including spray deposition, LSM, XDTM, squeeze casting, contact reaction, self-propagating high-temperature synthesis, reactive mechanical alloying and powder metallurgy. Common several aluminum-based composite material preparation process, as shown in Table 1. 2 Aluminum matrix composites at home and abroad 2.1 Foreign Aluminum Matrix Composite Technology Development Level The research of aluminum matrix composites began in the 1950s and has made great progress both theoretically and technologically in the past 20 years. Countries have invested a lot of human and material resources in R&D. It is the most studied and major composite material in metal matrix composites. Currently developed aluminum matrix composites mainly include SiC/Al, B/Al, BC/Al, Al2O3/Al, etc. Among them, B/Al composites have developed rapidly. At present, the United States can manufacture various B/Al profiles of more than 2 m. Pipes, etc. These materials are used on aircraft and can reduce the mass by 20%. Aluminum matrix composites have been widely used in the manufacture of wings, rudders, flaps, fuselage and skins of large aircraft such as annihilators and helicopters. US McDonnell Douglas used 1.8-2.25t fiber-reinforced aluminum matrix composites (FRM) on the F-15 fighter jet to reduce the fighter's mass by 2%. The former Soviet Aerospace Materials Research Institute applied boron-fibre-reinforced aluminum-based composite materials to the An-28 and An-72 aircraft body structures. While improving reliability, parts quality was reduced by 25%-40%. However, for a long time, due to the complex preparation process, strict requirements on the environment and equipment, and high cost, aluminum matrix composites are not widely used. There are three major manufacturers of powder-metallurgical particle-reinforced aluminum matrix composites: DWA Aluminum Composites of the United States, Alyn Corporation, and Aerospace Metal Composites (AMC) of the United Kingdom. These companies already have large-scale production capabilities and a wealth of product specifications. DWA aluminum matrix composites company's main product is based on 6092, 2009 and 6063 as matrix, SiC particles as reinforcement composites. 6092/SiC is its early product series, mainly plate and extruded profiles [2]. Aeronautical application example is 1980's Lockheed Martin Corporation of the United States will be 25% of the SiCP/6061A1 composite material used to make the stent placed instrument, its specific stiffness is higher than the 6075 aluminum alloy 65%. In the late 1990s, silicon carbide particle reinforced aluminum matrix composites were used in a large number of passenger aircraft. Pratt & Whitney starts with the PW4084 engine and uses DWA's extruded silicon carbide grain reinforced aluminum alloy matrix composite (6092/SIC/17.5p-T6) to produce fan outlet guide vanes for use with PW4000 series engines. Boeing 777 passenger aircraft. Particle-reinforced aluminum matrix composites have higher impact resistance than resin-based composites, and their erosion resistance is 7 times that of resin-based composites, and it is easy to find various damages and reduce the cost by more than 1/3. For the first time, Toyota Motor Corporation of Japan succeeded in using A12O3/A1 composite material to prepare the piston of the engine, which reduced the weight by 5% to 10% and improved the thermal conductivity by about 4 times. The connecting rod is the second component in a car engine that successfully uses metal matrix composites. The Al2O3/A1 alloy composite rod manufactured by Mazda of Japan is 35% lighter than steel rods, and has high tensile strength and fatigue strength of 560MPa and 392MPa, respectively, and a small linear expansion coefficient [3]. 2.2 Domestic Aluminum Matrix Composite Technology Development Level China has carried out more comprehensive research work on aluminum-based composite materials, including fiber-reinforced, particle-reinforced, laminated composites, spray deposition, and in-situ generation. It has made progress and is now becoming practical. In China, the use of high-pressure die casting SiCp/Al composites to make susceptors instead of W-Cu pedestals and package microwave power devices is expected to replace W-Cu, Mo-Cu and other materials in the packaging field. Based on the research of strengthening mechanism and preparation and processing, the development level of aluminum-based composites has gradually matured. For example, China's 1990s before the aluminum matrix composite plastic toughness and molding processing has not been a breakthrough, so the application is limited. Through years of research and accumulation, during the “10th Five-Year Plan†period, China has made important breakthroughs in the performance and research capabilities of aluminum-based composite materials. Despite lagging behind foreign countries, several typical aluminum-based composite materials (such as SiC/A1, A12O3/A1) are gradually Obtained recognition in the fields of aerospace, transportation and electronic instrumentation. In the future, with the steady improvement of research water and the development of new composite materials, aluminum matrix composites are expected to be used in many fields. In recent years, a new material with high strength, superior wear resistance, and good corrosion resistance, which can be widely used in aerospace manufacturing and automotive machinery industry - particle reinforced SiCp aluminum matrix composites, developed in Chinalco Shandong Branch success. This new type of aluminum matrix composite material has a density of only 1/3 of that of steel, but its specific strength is higher than that of pure aluminum and medium carbon steel. It has extremely strong wear resistance and can work stably at high temperatures of 300-350°C. Therefore, the United States, Japan and Germany and other developed countries are widely used in automotive engine pistons, gear boxes, aircraft landing gear, high-speed trains and precision instrument manufacturing, and formed a market-oriented production scale. At present, the international market price is 30,000 US dollars / t. Due to the fact that the casting process and the key process of deep processing for the production of end products using this material are immature, there are no enterprises in the country currently carrying out large-scale production. The successful development of this material not only fills the gap of large-scale production of aluminum-based composite materials in China, but also hopes to break the long-term dependence on imports in China[4]. Throughout the world, the research on the application of aluminum matrix composites has mainly focused on SiC particle reinforced aluminum matrix composites and has made great achievements. A few countries (such as the United States, Japan, and Canada) have entered the application stage and have achieved remarkable economic benefits. China's research in this area started late, most of them are still in the laboratory stage, and the depth and breadth of research are also very limited. Industrial research has only just begun. Aluminum matrix composites have been widely used in many fields such as automobile industry, aerospace, electronics, military industry and sports since its introduction. The key factors constraining its development (such as complex processes and high costs) are gradually being eliminated. Many countries have established factories to produce aluminum-based composite materials on an industrial scale. It is believed that in the near future, aluminum-matrix composite manufacturing processes will More simple, the cost will be lower and the scope of use will be broader. 3 Analysis of Application Fields of Aluminum Matrix Composites Particle-reinforced aluminum matrix composites and fiber-reinforced aluminum matrix composites have entered the commercialization stage. 3.1 Application in Transportation Tools Transportation vehicles have always been one of the most important civilian areas for aluminum-based composite materials. Taking into account the cost and related factors such as industrial applications, continuous fiber reinforced aluminum matrix composites and high-cost non-continuous reinforcement of aluminum matrix composites are excluded from this field, cheap particles and short fibers reinforced aluminum matrix composite There is still the possibility of large-scale application of materials. Aluminum matrix composites started earlier in the automotive industry. In the 1980s, Toyota Motor Corporation of Japan had already used aluminum silicate fiber reinforced aluminum matrix composites and successfully manufactured automotive engine parts such as piston wear rings and automobile connecting rods. U.S. Duralean Co., Ltd. has developed a car brake disc made of aluminum matrix composites reinforced with SiC particles, which has reduced its mass by 40% to 60%, improved wear resistance, significantly reduced noise, and improved frictional heat dissipation. The company also manufactures automotive engine pistons and gearboxes and other auto parts using SiC particle reinforced aluminum matrix composites. This automotive piston has higher wear resistance, better high temperature resistance and seizure resistance than aluminum alloy pistons, and has a smaller thermal expansion coefficient and better thermal conductivity. Automotive gearboxes made of SiCp/Al composite materials have significantly improved strength and wear resistance compared to aluminum alloy gearboxes. Aluminum alloy composites can also be used to make braking system components such as brake rotors, brake pistons, brake pads, and calipers, as well as automobile parts such as drive shafts and rocker arms. The Shanghai Jiaotong University and Ordnance Science Research Institute and other units also carried out a lot of practical work on the application of aluminum-based composite materials in automobiles. 3.2 Applications in Aerospace The development of aluminum matrix composites has made it possible to manufacture light and flexible airplanes and satellites with excellent performance in the modern aerospace field. Cereast Company adopts investment casting process to develop 20% Vo1+A357SIC composite material, use this material to replace titanium alloy to manufacture aircraft camera mirror frame with diameter of 180mm and weight of 17.3kg, which significantly reduces cost and quality, and improves thermal conductivity. . At the same time, the composite material can also be used to manufacture satellite reaction wheels and steering frame support frames. Instead of 7075, American DWA Company used 25% SiCp/6061 aluminum matrix composites instead of 7075 to manufacture aeronautical structural guides and angles, which reduced its density by 17% and its modulus by 65%. Cast SiC particle reinforced A356 and A357 composites can be used to make aircraft hydraulic pipes, helicopter landing gear, and valve bodies. Due to its own special advantages, aluminum matrix composites are widely used in the aviation, aerospace and military sectors and are widely used. For example, the Cr/Al composite material manufactured by DWC Special Composites Co., Ltd. is applied to NASA's satellite waveguides. It has a good conductivity and a small thermal expansion coefficient and is lighter than the graphite/epoxy waveguides originally used. About 30%. The Russian Aerospace Materials Research Institute uses B/Al composites for the An-28 aircraft's airframe structure, reducing the quality of its parts by about 25%. In addition, A1-based composites are also used to manufacture optical and electronic components. An ultra-light space telescope was developed at the University of Arizona. SiC/A1 composites were used to manufacture frames, brackets, and secondary mirrors, which greatly reduced the quality. U.S. DWA and British AMC will use SiC/Al in batches for EC-120 and EC-135 helicopter rotor systems to significantly increase component stiffness and life. The successful application of these key structural components shows that the study of the application of this material in the United States and the United Kingdom is quite mature. The SiC particle-reinforced aluminum matrix composite sheet will be used in the skin and tail reinforcement of advanced fighter aircraft in the future. The NASA uses graphite/aluminum composite materials as the spacecraft's 20m cargo tank shelf [4]. 3.3 Application in Weaponry Arms In the past 10 years, the decrease of fiber prices and the emergence of composite processes such as squeeze casting, vacuum suction casting and vacuum pressure infiltration have made it possible for composite materials to be used in large batches of conventional weapons. Fiber-reinforced aluminum matrix composites have become more widely used in weapons because of their good overall performance. A great deal of research has been invested in advanced countries. Pilot rods, pistons, tactical engine housings, and pilot rudders in engines have been trial-produced. Boards, warhead support frames, pull strings for military combat bridges, bridging tank bridges, and long-rod armor piercings. The United States Army conducted research on the manufacture of track shoes for Al2O3/A206 composite materials as early as the late 1970s. The use of composite materials to produce track shoes allowed the quality to be reduced from 544 to 680 kg of cast steel to 272 to 362 kg. Nearly 50%. The US Navy Ground Weapons Center uses SiC/A1 composites for ship structures and decks. It also intends to use this material for a variety of underwater projects as well as shells for torpedoes and mines. The pontoon bridge with a span of 30m made of silicon carbide fiber reinforced aluminum alloy composite material has a mass of only 5t, and its rigidity is 30% higher than that of aluminum alloy. With the continuous resolution of prices and technical issues, the application of such materials in the field of weapons will be even broader [5]. 3.4 Application in Electronic and Optical Instruments Aluminum matrix composites, especially SiC-reinforced aluminum matrix composites, are suitable for the manufacture of electronic devices such as lining materials and heat sinks due to their low thermal expansion coefficient, low density, and good thermal conductivity. The coefficient of thermal expansion of the SiC particle-reinforced aluminum matrix composite can completely match the thermal expansion of the electronic device material, and the electrical and thermal conductivity properties are also very good. In the application research of precision instruments and optical instruments, aluminum-based composite materials are used to manufacture telescope holders and secondary mirrors. In addition, aluminum matrix composites can also be used to manufacture many precision instruments and optical instruments such as precision parts of inertial navigation systems, rotating scanning mirrors, infrared observation mirrors, laser mirrors, laser gyros, mirrors, mirror bases, and optical instrument holders. Applied in the field of electronic packaging. Since the 1990s, some companies in developed countries have vigorously developed high-content SiCp/Al composites for electronic packaging. The development of high thermal conductivity and low thermal expansion metal matrix composites for electronic device packaging is one of the research and development trends of new materials. The United States has successfully developed SiCp/Al, Sip/Al, C/Al and other high-performance electronic packaging composite materials, which has become the key to solving the problem of rapid heat transfer and heat dissipation of electronic devices. The electronic packaging composite material developed is an aluminum matrix composite with an SiCp content of 60%-75%. 3.5 Other applications (1) Application of low-expansion aluminum matrix composites in spaceborne high-power multiplexers. (2) Application in the nuclear industry. B4C has the property of absorbing neutrons, so B4C particle reinforced aluminum matrix composites have a good application prospect in nuclear waste storage. DWA used 41% B4Cp/Al composite materials to produce nuclear waste dry storage barrels, and it has already achieved scale application. (3) Composite material wires. Electri Plast materials have a broad market prospect and are expected to be used in wire and cable and deicing systems in the aerospace field. Because the average mass of the material is 20% lighter than copper, cable quality can be reduced by several tons in miles of length. (4) Nano-micron hybrid reinforced aluminum matrix composites and their applications. The material can be widely applied to pistons, cylinder blocks, cylinder heads, rocker arms, brake discs, wheel hoops, track shoes, lightweight armor plates, and high-stability optoelectronic instruments and precision instrumentation components for civil and military motor vehicle engines. It can also be applied on ships, aviation and electronic devices. At present, the military high-power supercharged diesel engine pistons that have been produced using this material have passed the engine 800h Bench test and 1.0 x 104km sports car test, and its comprehensive performance is better than that of the German Mahle Company's products, and it fully meets the material requirements for imported pistons. (5) The application of graphite fiber reinforced aluminum matrix composites in the lens tube structure of space remote sensors. In the 1960s, the United States used B/Al composite materials to manufacture the main skeleton of the Space Shuttle Orbiter, which was 45% lighter than the originally designed aluminum alloy frame. The Hubble Space Telescope antenna suspension made of 42.2% P100 graphite fiber reinforced 6061 aluminum is a typical application of graphite fiber reinforced aluminum matrix composites on spacecraft. The Canadian Space Agency’s use of ultra-light laser scanning mirrors made of silicon carbide reinforced aluminum matrix composites and yttrium aluminum alloys will be used in the new generation of space vision systems (Space Vision Systems). A variety of other composite materials are also used in satellites' unfolded antennas and space camera mirrors. The Beijing Institute of Space Electromechanics used a discontinuous silicon carbide reinforced aluminum matrix composite (SiCp/Al) to manufacture the space camera's mirror box and mirror body. Beijing Aerospace Materials Research Institute prepared a high-density SiC/Al composite material for use as a space opto-mechanical structure using a pressureless infiltration composite method. In addition, a variety of resin-based carbon fiber composites have also been used to create space cameras hoods, lens tubes, and backplanes [6]. (6) The application of fiber reinforced aluminum matrix composites in transmission lines. Continuous alumina fiber-reinforced aluminum-based composite core transmission wire has been paid more attention by researchers because of its advantages of light weight, high strength, small creep and small coefficient of linear expansion. Continuous alumina fiber-reinforced aluminum matrix composites were first applied to transmission conductors as part of the conductors [7]. Aluminum matrix composites have characteristics that make them more widely used in the civil sector. In 1983, Toyota Motor Co., Ltd. successfully produced engine pistons from Al2O3/Al composite materials for the first time. Compared with the original cast iron engine pistons, the quality was reduced by 5% to 10%, and the thermal conductivity was improved by 4 times. Aluminum matrix composites are also widely used in the manufacture of other high-performance components such as bicycles, medical instruments and sports equipment, such as electronic packaging composites, computer discs, and automobile brake discs, which promote these industries as new economic growth points. . As a functional material, it is expected to be more widely used in the industrial sectors such as machinery, metallurgy and building materials. 4 Conclusion Throughout the world, the application research of aluminum matrix composites mainly focuses on SiC particle reinforced aluminum matrix composites, and has made great achievements. A few countries (such as the United States, Japan, Canada, etc.) have entered the application stage and have achieved remarkable economic benefits. Applications of aluminum matrix composites include applications in transportation vehicles, applications in the aerospace field, applications in weapons and weapons, applications in electronic and optical instruments, and so on. From the perspective of development trends, discontinuously reinforced aluminum matrix composites at the beginning of the 21st century will not only become an irreplaceable and important material in the aerospace and space fields, but will also gradually expand the civilian market. It is expected that this will be mass produced and applied in this century. Dining Room,Dining Room Tables,Round Dining Table,Modern Design Dining Room