Effect of twinning, slip, and inclusions on the fatigue anisotropy of extrusion-textured AZ61 magnesium alloy

► Twinning and detwinning was observed in the hysteresis loops of the AZ61 mg alloy. ► Fatigue cracks incubated from fractured intermetallic particles in the AZ61 mg alloy. ► Inclusions were more important in determining fatigue life than microstructure. ► The model predicted the different fatigue lives in the two orientations tested.