Analysis of ductility of nanostructured copper prepared by powder metallurgy

The strain rate sensitivity (m) was determined as a function of the strain rate using mechanical jump tests, on a nanostructured copper (grain size of 90 nm) prepared by powder metallurgy. The largest value is m = 0.050 ± 0.005, measured at 1 × 10⁻⁵ s⁻¹. Apparent activation volume was derived giving an insight of the micromechanisms involved in the plastic deformation. Nanostructured face centred cubic metals exhibit elongation due to their strain rate sensitivity and the related delay in the localisation of the deformation. The present analysis brings elements of the micromechanism involved in the plasticity, providing with the guide to design a relevant ultra-fine grained architecture with improved ductility.