Highly nanotwinned (nt) metals have shown a strength comparable to nanocrystalline metals, while maintaining other desired properties including ductility, conductivity, and thermal stability. However, the deformation mechanisms and mechanical stability of the nt metals is not yet fully understood but can be directly linked to large number of Sigma 3 boundaries. In this presentation, results from highly aligned nt samples tested in compression, torsion, and tension under various loading/testing conditions relative to the twin boundary (TB) direction will be presented. The microstructural evolution of the tested samples was analyzed before and after deformation for each loading configuration.
Overall, the nt structure was observed to be mostly stable, in which, to a significant extent, the nanotwins survived without major changes in twin size, orientation, or twin density. However, distinct differences in the overall deformation of the samples and in the extent of the changes were observed.