Study of strengthening mechanisms in Al-Cu and Al-Cu-Mg systems subjected to plastic deformation and T6 treatment

A series of Al-4Cu and Al-2Cu-2Mg wt.% alloys were synthesized through casting and subjected to plastic deformation to evaluate the interaction and contribution of the different strengthening mechanisms since the experimental Vickers microhardness test. The plastic deformation was performed by cold-rolling to achieve a 50% thickness reduction. The results show that solid solution strengthening is the main mechanism responsible for the total hardness enhancement of the alloys, and the Mg presents a higher hardening capacity for the solid solution strengthening than the Cu. For Al-4Cu alloy, competition between the annihilation of dislocations and the formation of precipitates generates an apparent low response precipitation hardening. Nevertheless, for Al-2Cu-2Mg alloy, the Mg addition allowed retard the dislocation annihilation induced an apparent higher response precipitation hardening.