High-cycle fatigue behavior of severe plastically deformed binary Zn-60Al alloy by equal-channel angular extrusion

High-cycle fatigue properties, mainly the fatigue strength and fatigue life, of two-phase Zn-60Al alloy subjected to severe plastic deformation (SPD) via multi-pass equal-channel angular extrusion (ECAE) using two different routes, route-A and route-B-C, were studied. The effect of ECAE processing parameters on the fatigue behavior of the alloy was investigated, and the stress amplitude versus number of cycles to failure (S-N) curves of the alloy were determined in the as-cast and multi-pass ECAE-processed conditions. The results showed that the fatigue performance of the alloy improved significantly through multi-pass ECAE. The fatigue endurance limit of the as-cast alloy reached to 146 MPa from 79 MPa. On the other hand, the fatigue properties of the ECAE-processed alloy were affected by ECAE parameters. and showed sensitivity to number of cycles and stress levels. Correlation of fatigue data showed that Basquin's law can be used to express the fatigue behavior of the multi-pass ECAE-processed alloy. Also, the ECAE processing changed the nature of fracture characteristics of the as-cast Zn-60Al alloy. (C) 2012 Elsevier B.V. All rights reserved.