| 摘要 |
PURPOSE:To manufacture the titled Al alloy, by melting an Al-Mn alloy having a specific composition containing Cr, Zr, and V and by casting the above at a specific cooling velocity. CONSTITUTION:The Al alloy consisting of 1.5-3.0% Mn as a principal component,one or more kinds among 0.05-0.4% Cr, 0.05-0.5% Zr, and 0.05-0.4% V, and the balance Al is melted, which is cast at a cooling rate of 50-5,000 deg.C/sec. In this Al alloy, all of Mn, Cr, Zr, and V enter into solid solution in Al and improve strength after heating at high temp. and, as to respective contents of the above components, strength is deteriorated when they are below the lower limits and, when they exceed the upper limits, giant compounds are crystallized out and the strength-improving effect is reduced. Moreover, when the cooling rate is within the above-mentioned range, Mn, Cr, Zr, and V are forced to enter into solid solution and strength is improved. The strength-improving effect is deteriorated because giant compounds are crystallized out when the above cooling rate is below the lower limit, and, even if it exceeds the upper limit, the strength-improving effect is little.
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