The fatigue crack propagation behavior of the forged Mg-Zn-Y-Zr alloy

The fatigue crack propagation (FCP) behavior of the forged Mg-Zn-Y-Zr alloy with different tempers was investigated. It revealed that the ΔKth values of the alloy were different. Among them, the ΔKth value of the T5 sample was obviously higher than that of the T6 sample. SEM fracture analysis indicated that at the stages 2 and 3, for the T5 sample, many deep dimples were distributed on the fracture surfaces, whereas the fracture surfaces of the T6 sample were almost completely composed of lamellar cleavage planes.