The precipitation processes in quenched Al-2.4Li-1.16Cu-0.8Mg(wt.%) alloy (8090) from the solid solution state (Tq = 803K) have been investigated via the Vickers microhardness measurements, scanning electron microscopy and differential scanning calorimetry. On the basis of Kissinger's analytical equation of the DSC thermograms, the overall activation energies associated with the transformation processes are evaluated. The activation energy associated with the formation of the GPB zones and s ' phase is determined as 82.433kJ/mol. Whereas the energy of their dissolution is 139.78kJ/mol. The activation energy associated with the formation of the S' phase is determined as 106.88 kJ /mol. In addition, the microstructural examination of the samples after various aging temperatures revealed that the resultant precipitates are intergranular.

PACS: 61.60.Dk