Cu nanowhiskers embedded in Nb nanotubes inside a multiscale Cu matrix: The way to reach extreme mechanical properties in high strength conductors

For the development of high pulsed magnets, reinforced Cu/Nb/Cu conductors composed of a multiscale Cu matrix embedding Nb nanotubes were produced by severe plastic deformation. While the Nb nanotubes exhibit a rather homogeneous microstructure with maximum grain size of 100 nm and 〈1 1 0〉 texture, a complex microstructure was pointed out in the Cu matrix with bimodal grain size distribution and duplex texture (〈1 1 1〉 and 〈2 0 0〉 orientations). The Cu/Nb/Cu system is also characterized by elevated tensile strength that follows a modified rule of mixture. The Cu nanofilaments inside Nb nanotubes behave as nanowhiskers.