Plasticity of nanostructured Cu-Nb-based wires : Strengthening mechanisms revealed by in situ deformation under neutrons

Cu/Nb/Cu conductors composed of a multiscale Cu matrix embedding Nb nanotubes were studied using in situ tensile testing during neutron diffraction. The evolution of lattice strains during deformation revealed the different elastoplastic regimes in the multiscale Cu matrix and the Nb nanotubes. The Cu nanofilaments embedded in the Nb nanotubes behaved as whiskers with a strong size dependence. The results are compared with Cu/Nb nanofilamentary wires and differences in strengthening mechanism are explained in terms of microstructure.