| 摘要 |
PURPOSE:To offer a superplastic Al alloy improved in corrosion resistance, by letting Al contain specified amounts of Mg, Zr, Be, Cr and Mn. CONSTITUTION:The alloy comprises 3-8wt% Mg, 0.2-0.6% Zr, 0.001-0.010% Be, optionally up to 0.3% Mn, up to 0.2% Cr and the balance being A and inevitable impurities. The ingot of the alloy is solution-treated, hot-worked with a reduction ratio of 30% or more at 180-220 deg.C, and then cold-worked with a reduction ratio of 50% or more at a room temperature or so. Thereafter, the alloy is annealed by 20-40% or so at 500-540 deg.C. The alloy structure is recrystallized and converted into a uniform fine grain one by the alloy composition, the solution treatment, the reduction sorking and the annealing treatment. Consequently, a superplastic Al alloy free from deterioration in its corrosion resistance is obtained. |
