Enhanced age hardening in an Al–Mg–Si alloy using high-speed compression

Abstract

The age hardening of an Al–Mg–Si alloy was examined by the effect of high-speed (10^{5 s−1}) compression prior to aging. The enhancement of the age hardening is brought about by the formation of vacancy clusters during high-speed compression. High resolution transmission electron microscopy reveals that these vacancy clusters form stacking fault tetrahedra. Following peak aging, vacancy clusters and aging precipitates coexist in the grain interior. The high aging hardness obtained following high-speed compression is most probably due to the combined effects of vacancy and precipitation hardening.