Study of work hardening of quenched and naturally aged Al–Mg and Al–Cu alloys

A comparative study on the work hardening of Al–Mg and Al–Cu alloys was carried out using a Kocks–Mecking–Estrin type analysis of stress–strain curves obtained in tension tests at constant loading rate. As a result of the analysis, dependencies of forest dislocation storage and dynamic recovery rates on the Mg and Cu concentration have been derived. The work hardening behavior and the microstructure formation in the Al–Mg and Al–Cu alloys were shown to be similar despite the opposite effects of Cu and Mg on stacking fault energy as well as the differences in solute atom size and friction stress. The influence of alloying on the work hardening peculiarities and the dislocation substructure evolution was discussed in connection with the effects of solute–dislocation interaction.