Effect of aging and dispersoid content on tensile properties of Al–0·6Mg–1 Si alloys

Abstract
Slip distribution was varied in a series of Al–Mg–Si alloys by changing the amount of manganese-bearing dispersoid present and by under- and overaging, which also altered the grain–boundary precipitate-free zones and hence the grain–boundary strength. Dispersoids are shown to increase ductility by slip homogenization. Slip is more heterogeneous in underaged alloys, but these show greater ductility than overaged alloys because the grain boundaries are stronger. Work-hardening rates increase with dispersoid content, although for a given dispersoid content, the underaged alloys have higher work-hardening rates. This effect is interpreted in terms of the effect of aging upon the properties of the grain-boundary regions. MST/340