Influence of the ECAP Processing Parameters on the Cyclic Deformation Behavior on Ultrafine‐Grained Cubic Face Centered Metals

Ultrafine-grained (UFG) materials are widely known to exhibit significantly improved fatigue properties when the fatigue life is regarded in a Wohler-SN-plot. More detailed, the achieved improvements in fatigue life significantly depend on the processing conditions of these UFG materials. In this work the influence of several equal channel angular pressing (ECAP) processing parameters on the fatigue properties of the AlMg model system with up to 2% of magnesium and on the technical alloy AA5754, namely AlMg3 are investigated. Most surprisingly, it is found that the material produced with route A (no rotation between ECAP passes), exhibit a higher fatigue life than the material produced by route Bc (90 degrees-rotation between ECAP passes). It is found that the different textures are responsible for that behavior. Moreover, the number of ECAP passes or the application of backpressure also significantly influences the fatigue life. In this context, relevant differences in the cyclic deformation behavior, microstructure, and damage mechanisms were discussed in this paper.