Abstract
Four-point bending fatigue test has been conducted to evaluate the effect of stress concentration factor on the fatigue properties of notched die-cast AM60 magnesium alloy. Notched specimens were tested with stress concentration factors ranging from 2.95 to 1.57. As the stress concentration factor increased from 1.57 to 2.55, the fatigue strength decreased from 75 MPa to 45 MPa. Further increase in stress concentration factor did not affect the fatigue strength. Fracture surface observation reveals that, the fatigue crack initiated at the notch tip. No casting porosity was observed near the crack nucleation region, indicating that casting defects, which were often found in the middle region of specimen thickness, did not influences the foregoing test results.
