Process–Structure Relationship of Extrusions Produced from Rapidly Solidified Al–Mg–Mn Powders

Abstract

Cold compacts have been prepared from Al–Mg–Mn rapidly solidified powders containing 7, 12, and 15 wt-%Mg. The compacts were subsequently extruded using a wide range of temperature compensated strain rates. Despite their high alloy content, each of these powder alloys could be extruded with relative ease. It is the fine nature of the powder state which assists the extrusion of these alloys which are inherently difficult to fabricate in the cast state. The mode of deformation is shown to occur by dynamic recrystallization. The subsequent microstructure is of a fine grain size and is shown to be related to the processing conditions. A relation-ship between the high temperature flow stress and the extruded structure is also indicated. Observations of the powder microstructure are reported. It is shown that the original powder structure is completely transformed during the extrusion process. PM/0364