Etude Thermique et Mécanique d’un Alliage d’Aluminium Al–Cu

Abstract

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