Refers to a sheet of metal coated with another metal plate to achieve without reducing the use of effects (corrosion resistance, mechanical strength, etc.) to save resources, reduce the cost of the effect. The composite method usually has the explosive compound method, the explosive rolling compound, the rolling compound and so on. Composite materials can be divided into composite plates, composite tubes, composite rods and so on. Mainly used in anti-corrosion, pressure vessel manufacturing, electrical construction, petrochemical, pharmaceutical, light industry, automotive and other industries.