Abstract
Upon noting the importance of the casting condition on the aging of Al-Zn-Mg cast alloys, the present study was conducted to see the effect of the cooling rate during casting on the aging characteristics. The results obtained are as follows:
(1) The aging characteristic depended strongly on the cooling rate during solidification; age hardenabilty decreased either when the cooling rate was high or when it was low.
(2) The cooling rate after solidification had smaller effect than that during solidification.
(3) Introduction of vibration during solidification was effective to prevent decrease of age hardenability when the alloys were rapidly solidified.
