| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-toughness aluminum casting by applying optimum heat treatment to an aluminum casting having a properly selected composition. SOLUTION: The high-toughness aluminum casting has a composition which consists of, by mass ratio, 1.65-6.0% Si, 0.1-0.5% Mg, a modifier, and the balance essentially Al with inevitable impurities and in which Cu content is regulated to <=0.5%. Moreover, thus aluminum casting gas >=17% elongation at 60-200μm dentrite secondary arm spacing (DAS 2) and >=19×10<4> J/m<2> Charpy impact value or further has >=180 MPa proof stress and >=270 MPa tensile strength. This aluminum casting is applicable to truck wheel or the like, and can attain weight reduction in a state that secures high toughness. In the method of manufacturing the high-toughness aluminum casting, solution heat treatment where rapid cooling is done without delay when the temperature of the aluminum casting reaches >550 to <575 deg.C is performed, followed by two-stage aging treatment.
|
