Low density aluminum, but the intensity is relatively high, close to or better than high-quality steel, good plasticity, can be processed into a variety of profiles, with excellent electrical conductivity, thermal conductivity and corrosion resistance, widely used in industry, the use of second only to steel . Some aluminum alloys can be heat treated to obtain good mechanical properties, physical properties and corrosion resistance. Hard aluminum alloy AI-Cu-Mg system, usually containing a small amount of Mn, heat treatment can be strengthened. It is characterized by high hardness, but poor plasticity. Super Al-Al-Cu-Mg-Zn system, heat treatment can be enhanced, is the highest strength at room temperature aluminum alloy, but poor corrosion resistance, high temperature softening fast. Wrought aluminum alloy is mainly Al-Zn-Mg-Si alloy, although the addition of many kinds of elements, but less content, which has excellent thermoplasticity, suitable forging, it is also known as forging aluminum.