Enhanced precipitation-hardening in Mg-Gd alloys containing Ag and Zn

The maximum hardness achievable in Mg-6 wt.%Gd-0.6 wt.%Zr alloy during isothermal aging at 200 and 250 degrees C can be increased substantially by controlled additions of Ag or Zn. A further increase in the maximum hardness can be achieved when Ag and Zn are added together. The remarkable improvement in precipitation-hardening in the resultant alloys is associated with a dense distribution of nano-scale basal precipitate plates. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.