Influence of Cd and In on the Formation Kinetics of the δ' Metastable Phase in Al-Li-In(Cd) Alloys

The influence of the cadmium and the indium on the kinetics of the δ’ metastable phase precipitation has been studied in Al-8.5at.%Li and Al-8.5%at.%Li- 0.2at.%In(0.3%at.%Cd) solid solutions. From the hardness isotherms the volumic fraction of the formed δ’ metastable phase is determined for different times of ageing at 150, 180 and 200°C. The incubation times of δ’ deduced from the precipitation kinetics show that In and Cd atoms retard the δ’ precipitation.