The flight equipment with a flight altitude of less than 100 km from the ground is called aircraft, and all kinds of deformed aluminum alloy and cast aluminum alloy used to manufacture aircraft are collectively referred to as aviation aluminum. Among them, the die castings used on the aircraft are produced by cast aluminum alloy, while the plates, profiles and wires of the aircraft are mostly processed by deformed aluminum alloy.
7150 Aluminum alloy with super strength, high toughness and corrosion resistance was successfully developed in the late 1970s. The emergence of
7150 high strength aluminum alloy achieved the goal of aluminum alloy with good corrosion resistance and alloy strength for the first time.
7150 Aluminum alloy is widely used in plates, profiles and castings in the aviation field. It is used to make high-strength structural parts of aircraft, such as outer wing beam of aircraft wing, main landing gear beam, front landing gear actuator, vertical tail joint and rocket nozzle structural parts.
7150 Aluminum Alloy after heat treatment has good performance in strength, spalling corrosion resistance and stress corrosion cracking resistance, fracture toughness and fatigue strength.
Aluminum parts of domestic ARJ21 aircraft account for three quarters of the net mass of the aircraft. Among them, the upper wing upper wall panel is made of 7150-t7751 aluminum alloy. At the same time,
7150 Aluminum alloy is also used to manufacture wing beams, fuselage stringers, fuselage frames, spacer frames, wing upper stringers, wing ribs and wing beams. Domestic C919 selects a large number of fourth generation aluminum alloys, such as 7050-t7452, 7150-t77511, etc.
7150 Aluminum alloy is also used in other domestic aircraft, such as Xinzhou 60 regional airliner, yun-20 heavy military transport aircraft, large amphibious aircraft ag6000, various fighter aircraft and other military aircraft.
At present, the demand for aviation aluminum in the aircraft field has two obvious characteristics: (1) there are many varieties and specifications of aluminum, high demand for product quality, complex product production processes, low yield and high price; (2) the effective utilization rate of aviation aluminum materials is low, and the effective utilization rate of some parts is even only a few percent. For example, the aircraft entry door is milled from a whole thick plate. Although the utilization rate of materials is relatively low, compared with the traditional entry door composed of more than 50 parts, the strength of the entry door has been greatly improved and the manufacturing cost has been reduced.
At present, the common aircraft in China include ARJ21 regional airliner, C919 trunk airliner, y-20 large jet transport aircraft (often referred to as large aircraft), all military aircraft and general-purpose aircraft. In the 20 years from 2015, China's aviation industry will get rapid and huge development. Under this trend, the annual compound growth rate of aviation aluminum can reach 10%, and its growth rate will exceed that of other major industries in the national economy.
After decades of research on high strength and high toughness aluminum alloys by Chinese researchers, China's research capacity on 7xxx series aluminum alloys has been in the advanced position in the world, and China's industrial application and production of 7xxx has also made some progress. However, in order to meet the production and development requirements of domestic aviation field and realize the complete localization of aviation aluminum materials, scientific researchers still need to continue research and practice. To sum up, the development of China's national defense and basic industry has an urgent demand for high-strength, high toughness and corrosion-resistant aluminum alloy, while the development level of domestic aluminum alloy industry still lags behind the international top level. Therefore, we must vigorously strengthen the research and innovation of high-strength, high toughness and corrosion-resistant aluminum alloy to support the development of China's national defense and basic industry.
