High strength and high electrical conductivity in bulk nanograined Cu embedded with nanoscale twins

Abstract

A bulk nanograined Cu sample embedded with nanoscale twins is produced by means of dynamic plastic deformation at cryogenic temperatures. It exhibits a tensile yield strength of 610MPa and an electrical conductivity of 95% IACS at room temperature. The unique combination of a high strength and a high conductivity is primarily attributed to the presence of a considerable amount of nanoscale twins which strengthen the material significantly while having a negligible influence on electrical conductivity.

High strength-high conductivity carbon nanotube-copper wires with bimodal grain size distribution by spark plasma sintering and wire-drawing

“…However, a specific type of grain boundary, the coherent twin boundary, was shown to strengthen electrochemically-deposited copper films without introducing additional electron scattering [5]. Similar results were reported for nanotwinned bulk materials [6] and wires [7,8] prepared using cryo-deformation. We have reported [9] an innovative approach combining spark plasma sintering (SPS) and room-temperature (RT) wire-drawing to produce Cu wires with both a high ultimate tensile strength (UTS) and high electrical conductivity.…”

“…2f) but there are no twins because the deformation during wire-drawing provoked their migration due to twin boundaries acting as non-regenerative dislocations sources [20]. Coherent twin boundaries were not observed, contrary to results reported for cryo-drawn wires [6][7][8]. No difference is observed between the microstructure of the Cu and CNT-Cu wires.…”

Enhanced Mechanical Properties and Electrical Conductivity in Ultrafine-Grained Al 6101 Alloy Processed via ECAP-Conform

“…SPD-processing leads to grain refinement followed by solid solution decomposition and subsequent precipitation and can be used as a new approach to enhance mechanical strength of pure metals with retention of electrical conductivity. It was applied to pure Cu [59,60], and recently has been used to process Cu [61,62] and Al-based alloys [19][20][21][22][23]63]. In our case, DA, in the course of ECAP-C, results in solid solution decomposition, which contributes to certain electrical conductivity enhancement ( Table 2).…”

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

“…44 Recent studies have shown that microstructural design in Al, Cu, and their alloys can result in a favorable combination of high mechanical strength with enhanced electrical conductivity. 45,46 It was demonstrated that both properties are primarily controlled by the microstructure of these materials of which the grain size, morphology of second phases and their distribution, as well as the dislocation structure are the most important parameters. In this case, nanostructuring the alloys by SPD is of special interest, and this raises fundamental questions concerning new mechanisms of strength and electrical conductivity as well as the innovation potential for practical applications of nanostructured materials.…”