Influence of severe plastic deformation on precipitation hardening in an Al-Mg-Si Alloy: Microstructure and mechanical properties

Abstract

Equal channel angular extrusion (ECAE) is applied to an age-hardening Al-Mg-Si alloy at temperatures where concurrent aging (dynamic aging) can occur to form fine β"-Mg2Si precipitates, and an ultrafine-grained matrix with high dislocation density can be maintained. This microstructure results in significant strength enhancement with little sacrifice in tensile ductility. The large plastic strain imposed by ECAE causes a fraction of the precipitates to dissolve into the aluminum matrix, which re-precipitate during subsequent aging treatment. ©2009 The Japan Institute of Metals.