Aluminum alloy is a kind of nonferrous metal structural materials widely used in industry, has been widely used in aviation, aerospace, automotive, machinery manufacturing, shipbuilding and chemical industry aluminum alloy. In recent years, with the rapid development of science and technology and industrial economic structure, increasing demand for the welding of aluminium alloy, the aluminum alloy welding research also will be thoroughly. Aluminum alloy is widely used to promote the development of welding technology of aluminum alloy at the same time, the development of welding technology and expanding the application field of aluminum alloy, so the aluminum alloy welding technology is becoming a hot spot of research.
Pure aluminum density (=2.7g/cm3), iron is about 1/3, the low melting point (660 C), aluminum is face centered cubic structure, so it has high plasticity (delta psi:: 32~40%, 70~90%), easy processing, can be made into various shapes, plates. Good corrosion resistance of pure aluminum; but the strength is very low, the annealed state sigma B is about 8kgf/mm2, it is not as a structural material. Through the long-term production practice and scientific experiments, people gradually to join the alloying elements and the use of heat treatment to strengthen aluminum, which has been a series of aluminum alloy. Add some elements to form the alloy also has high strength while maintaining the advantages of pure aluminum and light at the same time, a b value can reach 24 ~ 60kgf/mm2. This makes the "strength" (strength and the ratio of the proportion of b/ sigma rho) more than a lot of steel structure, become an ideal material, widely used in machinery manufacturing, transport machinery, power machinery and aviation industry, the aircraft's fuselage, skin, etc. often alloy manufacturing compressor with aluminum, to reduce weight. The welding of aluminum alloy instead of steel material, the structure can reduce the weight of more than 50%.