Influence of severe plastic deformation on aging of Al–Mg–Si alloys

The influence of severe plastic deformation induced by equal-channel angular pressing (ECAP) on the microstructure and aging was studied in two modified Al–Mg–Si aluminum alloys. The microstructure of both alloys after different heat treatments and deformation paths was characterized by X-ray diffraction and polarized-light microscopy. The effect of artificial aging was investigated on samples in the as-extruded condition after ECAP. The aging was monitored by hardness and electrical conductivity measurements. At higher aging temperature (170 °C), the alloys showed an increasing softening with time due to recovery or/and grain coarsening. At lower aging temperatures, the hardness remains almost constant owing to enhanced precipitation hardening.