Low-cycle Fatigue Behaviors of an As-extruded Mg-12%Gd-3%Y-0.5%Zr Alloy

Cyclic deformation and fatigue behaviors of Mg-12%Gd-3%Y-0.5%Zr（wt%,GW123K） alloy were investigated at room temperature under axial cyclic loading in strain controlled condition.It is shown that conventional extruded GW123K alloy maintained cyclic stability at strain amplitudes ranging from 2×10;to 10;.The pronounced symmetric hysteresis loops were also observed during cyclic loading.Fracture surface observations indicated that fatigue cracks mainly initiated at large Gd-riched phase or at inclusion clusters at surface or subsurface,and grain boundary（GB） and slip bands（SBs） are also preferential sites for micro-crack incubation.