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 × 10−3 to 10−2. 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.