Nanotwinned materials not only exhibit high strength but also possess substantial ductility. Their fatigue properties and damage behavior are very attractive for materials scientist. However, fully reversed tension-compression fatigue tests on nanotwinned materials under stress and strain control have not been carried out yet, mainly owing to the limitation of the sample thickness. In this study, bulk polycrystalline Cu samples with preferentially oriented nanoscale twins were synthesized by means of a direct current electrodeposition technique. Tension-compression fatigue tests were performed on the bulk nanotwinned Cu samples under constant stress and strain controlled fatigue tests. The cyclic stress responses, low-cycle fatigue life under strain control and high-cycle fatigue limit under stress control were explored. The underlying cyclic stress response associated with the effect of microstructural features, including TB orientation, twin thickness and twin lamellar length (i.e. grain size), were discussed.
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