Creep Behavior of Squeeze-Cast Mg–15Gd Alloy

The creep behavior of a binary Mg-15 wt.% Gd alloy was investigated over the temperature range from 523 K to 743 K, i.e., in both single-phase region (the hexagonal close-packed solid solution Mg) and two-phase plus Mg5Gd precipitates). prepared by squeeze casting technique. In higher range, at 723 specimens were treated situ annealing prior testing. At 673 below, tested cast state. interpreted terms viscous glide, where dislocation motion constrained presence solute atmospheres. controlled rate cross slip basal prismatic planes. temperatures 623 rationalized introducing threshold stress concept. 573 stresses required achieve experimentally measurable rates such that dislocations broke away atmospheres foreign atoms. Comparison with series magnesium alloys creep-tested same technique showed gadolinium can be favorable creep-resistance enhancing element.