Résumé:
The aluminum-copper alloys of the 2xxx series are widely used, particularly in the
automotive, aeronautical and urban industries. To meet the different requirements for the
different practical applications, various heart treatment processes are commonly performed on
the materials. The researchers worked to find available and less expensive materials to cover
the required needs.
Our work aims at the thermal and mechanical study of an aluminum alloy Al-4%Cu
which is widely used in industry. For this, the following investigation methods were used:
optical microscopy (MO), differential calorimetry (DSC) and the Vickers microdurometer
(HV).
The optical microstructures of the alloy, the precipitation kinetics of the alloy and the
microdorometer are studied. Microdurometer resultants showed that various peaks appeared on
the DSC curves, which were characterized to identify precipitation or dissolution processes of
different metastable phases. Certain peaks on the DSC curve are used to calculate precipitation
kinetic parameters, namely the activation energy. The results show that the activation energy
of the transformation process varies significantly from one phase to another.
The decrease in the heating rate favors the acceleration of the precipitation sequence in the
Al-4%Cu alloy. It is as follows: Zones G.P → Phase ’’→ Phase ’→ Phase .
The formation of the intermediate phases ’’, ’ and the stable phase require activation
energies of approximately 50 KJ/mol, 77 KJ/mol and 104 KJ/mol respectively
