Fatigue-property enhancement of magnesium alloy, AZ31B, through equal-channel-angular pressing

The fatigue behavior of magnesium-alloy, AZ31B, prestrained by equal-channel-angular pressing (ECAP) was studied as a function of the accumulated plastic-strain level and the orientation of the samples (along and perpendicular to the ECAP pressing direction). The material was processed via route B-C, at 200 degrees C, for 1, 2, and 8 passes, with and without a back pressure (BP) applied on the billet during ECAP. The low-cycle fatigue behavior of the AZ31B alloy is shown to be anisotropic and texture dependent. Due to the initial texture orientation, the specimens loaded parallel to the ECAP pressing direction have a longer fatigue life than the samples loaded perpendicular to it. The low-cycle fatigue life of the AZ31B alloy is enhanced by ECAP. The fatigue-property improvement is discussed in light of the grain-size refinement, enhanced ductility, and texture evolution.