Dislocation movements during creep in a die-cast AM50 magnesium alloy

Abstract

Tensile creep tests were combined with detailed transmission electron microscopy in order to characterize the dislocation movements during creep of the die-cast AM50 magnesium alloy. TEM observations indicate that dislocations are introduced within the primary α-Mg grain interior in the die-casting process, which consist of both the basal and non-basal segments. The non-basal segments of dislocations, having smoother curvature in as die-cast state, partially exhibit steps parallel to the basal plane during high temperature exposure. The basal segments of dislocations are able to bow out and glide on the basal planes under the influence of a stress, and the non-basal segments and/or jogs follow the basal segments with the help of climb during creep.