EFFECT OF STRUCTURE TRANSFORMATION ON TRANSIENT CREEP-BEHAVIOR OF AL-AG SYSTEM

The transient creep of Al-16 wt% Ag and Al-16 wt% Ag-0.1 wt% Zr solid solution alloys is investigated in the temperature range 428 to 673 K for various ageing times under constant load. The subsequent decrease and increase in the values of creep parameters n and beta with increas ing ageing times and ageing temperatures has been explained on the bas is of structure transformations occuring in Al-Ag alloys. It was found that the addition of Zr to Al-16 wt% Ag alloy accelerates the precipi tation of GP zones, gamma'-phase, and gamma-phase. TEM investigations confirmed the above effects. The mean values of the activation energy of both alloys were found to be equal to that quoted for dislocation i ntersection.