The relationship between microstructure and creep resistance in die-cast magnesium-rare earth alloys

Die-cast Mg-La, Mg-Ce and Mg-Nd binary alloys varying in composition have been used to investigate creep resistance and its relation to microstructure. The remarkable differences in creep resistance observed in these alloys are shown to be related to different levels of rare earth (RE) solute supersaturated in the alpha-Mg matrix. The results seem to suggest that strengthening of the alpha-Mg matrix by solid solution and/or precipitation is more important than grain boundary reinforcement by intermetallic phases for the creep resistance of Mg-RE alloys.