Effects of loading strain rate and stacking fault energy on nanoindentation creep behaviors of nanocrystalline Cu, Ni-20 wt.%Fe and Ni

Creep behaviors of nanocrystalline (NC) Cu, Ni-20(wt.%)Fe and Ni with comparable grain sizes were examined by nanoindentation tests (the above graphs are just for NC Cu). It was showed that the creep behavior depends on loading strain rate and stacking fault energy (SFE). Comparing the initial creep rates of three NC materials with those predicted by the models of the Coble creep and the grain boundary (GB) sliding could help us determine the possible mechanisms responsible for the creep deformation of NC metals and alloys in the nanoindentation tests.303