Cyclic stress-strain response and low-cycle fatigue damage in ultrafine grained copper

The ECAE route 16E gives superior fatigue performances as it provides for stable cyclic stress-strain response and more homogeneous plastic deformation than routes that are composed of lower number of ECAE passes. Still, the in situ fatigue tests indicated that fatigue damage occurs on a very localized scale, and thus, additional strengthening mechanisms need to be exploited to obtain UFG materials that display enhanced microstructural stability.