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Stress-strain curves of the EN AW 6082 aluminium alloy with 1.2 Si-0.51 Mg-0.75 Mn (wt.%) were determined by the uniaxial compression tests at temperatures of 450–550 °C with a strain rate of 0.5–10 s−1. The initial structure state corresponded to three processing types: as-cast structure non-homogenized or homogenized at 500 °C, and the structure after homogenization and hot extrusion. Significantly higher flow stress appeared as a result of low temperature forming of the non-homogenized material. Hot deformation activation energy Q-values varied between 99 and 122 kJ·mol−1 for both homogenized materials and from 200 to 216 kJ·mol−1 for the as-cast state, while the Q-values calculated from the measured steady-state stress were always higher than those calculated from the peak stress values. For the extruded state of the 6082 alloy, the physically-based model was developed to reliably predict the flow stress influenced by dynamic softening, temperature, strain rate, and true strain up to 0.6.

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The effect of Sc and Zr addition on microstructure and hardness development in a commercial as-cast and solution-treated (530 °C/45 min) AA6082 alloy was studied. The electrical resistivity decrease and hardness increase in the temperature range 180 – 300 °C are caused by precipitation of β′′ and/or β′ needles of the Mg – Si system. Precipitation and morphology changes of Al – Mn – Fe system phases in AA6082 and AA6082-ScZr alloys influence the resistivity significantly, but have a negligible effect on hardness. The initial hardness of Sc and Zr containing AA6082 alloys is higher mainly due to the presence of Al3(Sc, Zr) particles. This difference is less pronounced in the peak-hardening state. Natural ageing of solution-treated alloys influences microstructure development in both alloys when annealed subsequently up to 240 °C.