Fatigue strength dependence on the ultimate tensile strength and hardness in magnesium alloys

•Fatigue strength depends on ultimate tensile strength and hardness in Mg alloys.•The slopes of linear fatigue models depend on deformation and fracture mechanisms.•The deformation mechanism is related to heat treatment the material has undergone.

The relationships between fatigue strength and ultimate tensile strength as well as hardness have been studied in high-strength NZK alloys (Mg–yNd–zZn–xZr) and other magnesium alloys. In the absence of casting defects, clear linear relationships have been found between the fatigue strength and the ultimate tensile strength and the hardness values in these magnesium alloys in both T4 (solutionized) and T6 (solutionized and aged) conditions. The fatigue strength models developed in this work alloys can be directly applied to other defect-free magnesium alloys.