A combination of severe plastic deformation and ageing phenomena in Al–Mg–Si Alloys

In this paper static and dynamic strain ageing behavior in Al–Mg–Si alloys related to equal channel angular pressing (ECAP) was investigated. In order to examine the combined plastic deformation, solution treatment and ageing effects on strengthening characteristics, experimental results of ageing without ECAP, pre-ECAP ageing, post-ECAP ageing and dynamic ageing inside of ECAP die were compared. In particular, the effects of ageing temperature, ageing time, strain rate in ECAP, and sequence of heat treatment and ECAP on Vickers hardness were discussed. To achieve a higher hardness, an optimum ageing cycle combined with ECAP process is presented based on the results of current study. By employing the proposed schedule the hardness value was increased from 86 HV (as-solution treatment) to 138 HV (peak hardness of the current schedule).

► Static and dynamic aging during warm equal channel angular extrusion. ► The effect of pre-straining by ECAP on ageing time. ► The suggestible condition for achieving the highest hardness value. ► Dynamic ageing of the alloy showed that the ageing time-scale is reduced.