| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing precast-formed billet of an aluminum alloy for a transportation apparatus in a simple process by which the reduction of cost is promoted and the product to be obtained is made homogeneous. SOLUTION: An aluminum alloy which has a composition containing, by weight, 1.0 to 7.0% Cu, <=0.35% Zn, and <=1.5% Fe, and at least one or more kinds selected from 0.001 to 0.5% Ti and 0.0001 to 0.5% B, and at least one or more kinds selected from 0.2 to 2.0% Mg, 0.15 to 1.5% Mn, 0.15 to 1.5% Si, 0.3 to 3.0% Ni, 0.03 to 0.35% Zr and 0.03 to 0.25% V, and the balance substantially Al and in which the intervals of dendrites are <=200μm is produced. Next, working strains are introduced therein at a strain ratio of 5 to 50%, at a working introduction rate of <=50 mm/sec., and, at a temperature lower than the recrystallization temperature thereof by cold frame mold forging. After that, its temperature is raised to a solidus temperature or an eutectic temperature or higher, and the temperature is held so that a liquid phase ratio reaches 20 to 80% to apply precast forming thereto.
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