Aluminum alloy is one of the most widely used nonferrous metal structural materials in the industry. With the rapid development of industrial economy, the demand for aluminum alloy welded structural parts is increasing day by day. At present, aluminum alloy is the most widely used alloy.

Aluminum alloy is low in density, but high in strength, close to or more than high quality steel, good in plasticity, can be processed into various profiles, with excellent conductivity, thermal conductivity and corrosion resistance, widely used in industry, usage is second only to steel. Some aluminum alloys achieve good mechanical, physical and corrosion resistance by heat treatment. Hard aluminum alloy belongs to ai-cu-mg series and generally contains a small amount of Mn, which can be strengthened by heat treatment. It is characterized by high hardness but poor plasticity. The superhard aluminum belongs to Al one Cu – Mg – Zn series, which can be heat treated and strengthened. Wrought aluminum alloy is mainly Al – Zn – Mg – Si series alloy, although the variety of elements is added, but the content is less, so it has excellent thermoplastic, suitable for forging, so it is also known as forged aluminum alloy