A comprehensive evaluation of parameters governing the cyclic stability of ultrafine-grained FCC alloys

The current paper presents results of a thorough experimental program undertaken to shed light onto the mechanisms dictating the cyclic stability in ultrafine-grained (UFG) alloys with a face-centered cubic structure. Cyclic deformation responses of several copper- and aluminum-based UFG alloys were investigated and the corresponding microstructural evolutions were analyzed with various microscopy techniques. The important finding is that a larger volume fraction of high-angle grain boundaries and solid solution hardening significantly improve the fatigue performance of these alloys at elevated temperatures and high strain rates, and under large applied strain amplitudes.

► The fatigue response of ultrafine-grained Cu and Al alloys was investigated.
► Stabilizing elements restrict grain boundary mobility and promote cyclic stability.
► Elevated temperatures facilitate grain coarsening and hinder cyclic stability.
► High-angle grain boundaries promote cyclic stability.
► The cyclic stability of UFG alloys is a multi parameter problem.