The invention relates to a metal composite material and a preparation method thereof, and particularly discloses a stainless steel/aluminum composite material and a preparation method thereof. The material includes a three-layer structure formed by hot rolling, the bottom layer is a stainless steel layer, the middle layer is an aluminum alloy layer, and the surface layer is a pure aluminum layer; the aluminum alloy contains Cu, Mg, and Mn elements. The preparation method of the material includes cleaning the surface of the raw material plate; then laminating the stainless steel plate and the aluminum alloy plate, hot rolling and heat treatment to form a hot rolled plate; laminating the pure aluminum plate on the aluminum alloy layer of the hot rolled plate Rolling, heat treatment. The stainless steel aluminum aluminum clad sheet coil of the invention has good binding force, and is not deformed, wrinkled or layered in the subsequent stamping and other processes.


Stainless steel has the advantages of high strength, good rigidity, strong corrosion resistance, good formability at room temperature, etc. It is widely used in various industries. However, when stainless steel is used as a shell for electronic products such as mobile phones, its surface decoration technology is limited, limited to several decorative effects such as mechanical polishing, wire drawing, sand blasting, PVD, electroplating.At present, there is a stainless steel/aluminum composite material formed by hot rolling a pure aluminum layer on the surface of stainless steel. On the one hand, this material maintains the characteristics of high strength, good rigidity, and superior mechanical properties of stainless steel; on the other hand, because the surface is a pure aluminum layer, it can be treated by electrolytic polishing and anodizing to form a high-strength, high-gloss, colorful shell. However, in the prior art, the bonding strength of pure aluminum and stainless steel is poor, which may cause deformation, wrinkling, delamination and other phenomena during subsequent processing (such as stamping), which affects poor product quality.The technical problem to be solved by the present invention is: in the prior art, in the stainless steel/aluminum composite material, the bonding force between aluminum and stainless steel is poor. Thus, a stainless steel aluminum aluminum clad sheet coil with a strong binding force is provided.
Stainless steel aluminum aluminum clad sheet coil includes a three-layer structure formed by hot rolling, a bottom layer is a stainless steel layer, an intermediate layer is an aluminum alloy layer, and a surface layer is a pure aluminum layer; the aluminum alloy contains Cu, Mg, and Mn elements.
 The invention also provides a method for preparing the above stainless steel/aluminum composite material.
 -A preparation method ofstainless steel aluminum aluminum clad sheet coil, which includes the following steps:
(1) Surface pretreatment: clean the surface of stainless steel plate, aluminum alloy plate and pure aluminum plate;
 (2) One-time hot rolling: laminating stainless steel plates and aluminum alloy plates, heating them and feeding them into rolling mills for composite rolling, and then performing heat treatment to form one hot-rolled plate;
 (3) Secondary hot rolling: The pure aluminum sheet is laminated on the aluminum alloy layer of the primary hot rolled sheet, after heating, the composite rolling is performed, and then the heat treatment is performed.
The stainless steel clad aluminum plate provided by the invention has strong binding force, and is not deformed, wrinkled or layered in the subsequent processing, and the finished product shell has good mechanical strength, high surface appearance, high gloss and colorful colors .