Partition of Er among the constituent phases and the yield phenomenon in a semi-continuously cast Mg-Zn-Zr alloy

This paper describes an increased partition of a rare earth element Er to the Mg matrix in a semi-continuously cast Mg-1.5Zn-0.6Zr alloy, resulting in a significant increase in elongation, as well as a refined grain size and a higher yield strength in the extruded Er-containing alloys compared with the Er-free alloy. Yield phenomena with distinct upper and lower yield points were also observed, caused by the strong interaction between solute atoms and dislocations as a result of Er addition. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.