Current Status of Aluminum Alloy Sheets for Automobile Body
Aluminum alloy sheets that can be used for automobile body mainly include 2000 series, 5000 series and 6000 series alloys. The research status of aluminum alloys for automobile body sheets is introduced from three aspects: microalloying and heat treatment of aluminum alloy sheets for automobile body, advanced forming technology of aluminum alloy sheets for automobile body and finite element research of aluminum alloy sheets for automobile body.
Aluminum alloys used in automobiles mainly include die castings, forgings, extrusions and sheets. Among these four types of products, deformed aluminum alloy sheets used for stamping have the highest technical requirements among aluminum alloy sheets. Deformed aluminum alloy sheets can effectively reduce the weight of automobiles when replacing traditional steel. For example, compared with steel parts, the weight of aluminum alloy engine cover can be reduced by more than 40%. At the same time, due to the good thermal conductivity of aluminum alloy, the temperature of the engine can be effectively reduced. In addition, the special properties of aluminum alloy can effectively reduce the damage to pedestrians during collision, which is conducive to meeting the implementation of pedestrian collision protection regulations. At present, the aluminum alloy sheets used for automobile bodies mainly include 5000 series and 6000 series, and common material grades include 5052, 5754, 5182, 6016, 6014, and 6181. In addition, a small amount of 2000 series sheets are also used in automobiles. The performance requirements of aluminum alloys for automobile covering parts are extremely high, so key links must be controlled during the production process. In the raw material production stage, the materials need to be designed, smelted and cast. After homogenization heat treatment, the materials are prepared into sheets of different thickness specifications through cold and hot rolling processes. Finally, the organization and second phase are controlled by heat treatment to achieve products that meet production needs. In the entire production process, reasonable composition design and heat treatment process formulation are necessary prerequisites to ensure high-quality sheets. However, compared with traditional mild steel, aluminum alloy sheets still have disadvantages in the forming process, such as large rebound and easy cracking. These disadvantages need to be optimized and compensated in molds and processes. Therefore, in order to solve the problems of cracking and rebound, finite element methods are usually used to conduct research on the application of aluminum alloy sheets from the aspects of forming technology or process.
Adding trace elements to aluminum alloys can improve their comprehensive mechanical properties. For example, adding rare earth elements to aluminum alloys can improve and refine the structure of aluminum alloys, improve the mechanical properties of aluminum alloys, and prevent segregation and remove impurities in the alloy. After a certain heat treatment process, the aluminum alloy plate can improve its structure and mechanical properties and have better formability.
