Large enhancement in mechanical properties of the 6061 Al alloys after a single pressing by ECAP

Microstructure and Mechanical Properties of an Al-Li-Mg-Sc-Zr Alloy Subjected to ECAP

“…There exists no potential for further work-hardening after this TMP. As a result, uniform elongation does not exceed 3%-5% [7,17]. It was shown that it is possible to increase strength by ECAP with ductility remaining essentially unchanged [19].…”

“…Second, an aluminum alloy in a condition of supersaturated solid solution produced by initial water or oil quenching is processed by ECAP at a temperature below, equal to or slightly higher than the aging temperature (Figure 1b). Finally, the processed alloy is subjected to artificial aging [6][7][8][9]17,19,21,[25][26][27]. This is the most popular TMP route.…”

“…High YS originated from a combination of dislocation strengthening and dispersion strengthening. However, the total elongation decreases by almost a factor of two [6][7][8][9]17,21,26,27]. Decreased ductility is attributed to low work-hardening rate [6].…”

“…It is obvious that only the combination of grain size strengthening with precipitation hardening can significantly affect the strength of these aluminum alloys. The formation of a UFG microstructure significantly affects the size of second-phase precipitations and their distribution within the aluminum matrix [5][6][7][8][9][10]. Therefore, mechanical properties of age-hardenable aluminum alloys subjected to ECAP depend critically on the aging response including precipitation kinetics and sequence, origin of dispersoids and the precipitate morphology.…”

“…As a result, the achievement of increased yield stress (YS) in age-hardenable aluminum alloys is not a trivial task. A positive effect of ECAP on YS is reported in a limited number of studies [5,[7][8][9]17,19,20]. It is worth noting that in all these works the temperature of final aging was lower in comparison with aging temperature used to achieve optimal YS in their coarse grained (CG) counterparts.…”