2008 Volume 2 Issue 4 Pages 487-495
The fatigue properties of extruded magnesium alloy AZ31 were evaluated using material processed under two different extrusion ratios and two different extrusion temperatures. The effect of the extrusion ratios and extrusion temperatures on the fatigue lives and crack propagation behavior is discussed. The fatigue crack initiation and propagation processes were observed by the replica method. It was found that cracks initiated early in the fatigue process, and therefore the total fatigue life can be approximated as the crack propagation life. The crack propagation behavior observed in those materials was analyzed using a modified linear elastic fracture mechanics parameter, M. The relation crack propagation rate vs. M parameter was found to be useful in predicting fatigue lives and crack propagation curves.
