Precipitation, recovery and recrystallization under static and dynamic conditions for high magnesium aluminum-magnesium alloys

Abstract

Previous studies of the mechanical behavior of warm rolled high magnesium aluminum-magnesium alloys have shown that excellent tensile properties can be developed in these materials. Several questions raised in these previous efforts regarding recrystallization and precipitation of the intermetallic 3 phase are addressed in this thesis. It is shown that, for temperatures T < T (where T is the solvus temperature) the only microstructural change is the precipitation of the 3 phase and no recrystallization occurs, even with prior cold work. Further studies of microstructures developed during warm working, with and without prior cold work, also indicate that precipitation and recovery dominate the microstructural changes in warm rolling at temperatures below the solvus for the alloy. Recrystallization will occur readily, but only at temperature in excess of the solvus. Strengthening by warm working, then, occurs by mechanisms similar to cold work strengthening in solid solution alloys.