To provide an Al alloy for a brake disk with excellent color tone after anodizing treatment and excellent in strength, fatigue strength, stress corrosion cracking resistance and formability and to provide its producing method.
This Al alloy for a brake disk has a composition containing, by mass, 0.05 to 0.25% Fe, 0.5 to 1.0% Mn, 0.05 to 0.2% Zr, 0.01 to 0.2% Cu and 3 to 4% Mg, and the balance Al with inevitable impurities, and the ratio 50 to 90 vol.%, is occupied by subgrain structure. In the method for producing an Al alloy for a brake disk, the ingot of an Al alloy having the composition similar to that of the above Al alloy is subjected to homogenizing treatment at 430 to 480°C, and then to hot rolling in which finishing temperature is controlled to 200 to 300°C and is thereafter subjected to finish annealing.
TAKAGI YASUO
SASAKI YASUNORI
NISHIMURA TOMOHIRO
