摘要 |
Provided is a superplastic forming aluminum alloy in rolled form which exhibits superplasticity and has improved corrosion resistance, weldability, and strength and fatigue property after superplastic forming, eliminating a need for heat treatment after superplastic forming. Preferred alloys have an excellent outer appearance of grey to black color after anodization. The alloy consists essentially of, in % by weight, 2.0-8.0% of Mg, 0.3-1.5% of Mn, 0.0001-0.01% of Be, an optional element selected from C, V, and Zr, an optional grain refining agent of Ti or Ti and B, less than 0.2% of Fe and less than 0.1% of Si as impurities, and the balance of Al, wherein intermetallic compounds have a size of up to 20 mu m, and the content of hydrogen present is up to 0.35 cc/100 grams. Particularly when a minor amount of Ti or Ti and B grain refining agent is contained, Mn precipitates have a size of 0.05 mu m or larger, and the Si content in entire precipitates is less than 0.07% of the total rolled alloy weight, the rolled alloy is grey or black on the anodized surface.
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