Cyclic deformation response of ultrafine pure Al

The cyclic deformation response of ultrafine pure Al produced by cryo-rolling was investigated using low-cycle fatigue and electron microscopy. The ultrafine pure Al was cyclically deformed under a fully reversed total strain control (R = −1) corresponding to a plastic strain amplitude range of 8 × 10−4 and 1.4 × 10−2. It was found that cryo-rolled pure Al is very susceptible to cyclic softening, resulting in a much lower fatigue life compared with the coarse-grained counterpart. Shear banding and associated grain coarsening were the most prominent microstructural features of the cyclically deformed cryo-rolled pure Al. Furthermore, annealing led to a slight decrease in the cyclic softening rate, giving a slight increase in the fatigue life of cryo-rolled Al.