Aluminum alloy has a series of advantages such as low density, high specific strength, good corrosion resistance and formability, low cost, and has a wide range of application prospects and irreplaceable status in aviation, aerospace, shipbuilding, nuclear industry and weapons industry. In aviation, aluminum alloy is the main material for aircraft body structure. Although the density of aluminum alloy is low, its strength is relatively high, close to or more than high-quality steel, good plasticity, can be processed into various profiles, with excellent electrical conductivity, thermal conductivity and corrosion resistance, widely used in industry, the use of second only to steel.