Abstract
Following the previous report on the aging curves of Al-4wt%Cu-Sn alloys, those of Al-4wt%Cu-Cd alloys with Cd content up to 0.064%, were investigated in relation to aging temperatures (TA), aging times (tA) and Cd contents by electrical resistivity measurement. The specimens were solution-treated at 520°C for 2hr, quenched and subsequently aged mainly at temperatures ranging from 0 to 200°C.
The results obtained were as follows:
(1) The aging curves varied continuously with TA, tA and Cd contents, and the precipitation process of ternay alloys seemed to be different from that of Al-Cu binary alloy. These results were the same as those of Al-Cu-Sn alloys previously reported.
(2) As for the aging curves at low temperatures, for instance, from -13 to 25°C, the changes of the initial rate of aging with the aging temperature and Cd content were examined, leading to the result that they were hardly explained by the vacancy-trap model so far postulated.
