In recent years, the progress of automobile lightweight development has accelerated, and more and more automobile manufacturers have begun to use aluminum alloy plates as the main material for automobile manufacturing, which is also due to its excellent performance and meets the needs of enterprises.

What are the performance requirements of aluminum alloy sheets for automobiles?

1.Surface treatment and coating performance

Before the steel is painted, its surface should be treated with acid washing and phosphating, so as to improve the bonding force between the surface of stamping parts and the paint and improve its corrosion resistance. Because there will be an oxide film on the surface of aluminum alloy, the surface treatment before painting is different from that of steel materials. Instead of general acid phosphating, chromizing treatment is adopted. Considering the toxicity of hexavalent chromium to human body, chromium-free or low chromium treatment technology has been developed in recent years, which can meet the needs of enterprises.

2.A certain anti-aging stability

The characteristic that the aluminum alloy sheet does not age when stored at room temperature is called anti-aging stability. Because aging will cause the alloy to elongate at the yield point when it is stretched and deformed, that is, the Lude ribbon, which will cause uneven surface deformation and wrinkling during stamping, which will affect the appearance of the stamped parts; the sheet is often required to be stamped from the factory to the stamping of the parts. Shipping and storage for some time, usually requires the board to be stored at room temperature for 6 months without aging.

3.Good bake hardenability

Auto stamping parts will also be aged when they are subjected to paint baking after stamping, so that the characteristic of increasing their yield strength is called bake hardening. High bake hardenability will give the part high dent resistance. Since the paint baking process of most automobile companies is currently designed for steel plates, and the bake hardenability of aluminum alloys is significantly different from that of steel, the bake hardenability is the best compatible with the paint process of steel plates; the bake hardenability of materials can be assessed according to relevant standards.

4.Good flanging ductility

When the automobile outer cover is stamped and flanged, the resistance of the sheet to cracking is called flanging ductility. Therefore, it is required that the aluminum alloy sheet should have good flanging ductility to ensure that no cracking occurs during flanging. The flanging ductility of the sheet is related to the total elongation of the sheet, as well as the internal organization of the material. The ductility of flanging can be tested by cold bending test, but the sensitivity of strain rate is not considered in the usual cold bending, and the deformation is fast and the strain rate is large during stamping flanging, so there is a higher requirement for flanging ductility.

5.Better surface finish

The aluminum alloy sheet is different from the steel plate, and its grain size is much larger than that of the steel. Under the coarse grain, if the grain size is not uniform, the surface of the stamping part will be deformed like a rope loop along the rolling direction. , This kind of surface defect is also called Luoping line, which leads to inconsistent surface gloss after paint, so automobiles need to have better surface gloss.

6.Good formability is required

The formability of a sheet refers to its ability to withstand shape changes during the stamping process. Formability can be evaluated by a formability test. At present, there have been a lot of test results on the formability of steel sheets, but the test results of the formability of aluminum alloy sheets can fully meet the needs of automobiles in terms of performance.

MC Aluminum specializes in the production of various specifications of aluminum sheets, aluminum coils, aluminum circles and other aluminum products. The specifications are complete and the production capacity is huge, which can meet your individual processing needs. MC Aluminum can provide you with the latest product quotations. Looking forward to your consultation!