Formation of a state with high strength and electrical conductivity in the Cu-0.5%Cr-0.2%Zr alloy

Elena Sarkeeva,Marina Abramova,Wei Wei,S Bratan,S Roshchupkin,S Gorbatyuk,S Leonov

doi:10.1051/matecconf/201712902030

Elena Sarkeeva, Marina Abramova + Show 5 more

Open Access

https://doi.org/10.1051/matecconf/201712902030

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Abstract

The effect of severe plastic deformation by high pressure torsion (HPT) and subsequent aging on the formation of a high-strength state with sufficient electrical conductivity in the Cu-0.5%Cr-0.2% Zr (wt.%) alloy is investigated. It is shown that as a result of HPT and subsequent aging a high-strength state with a tensile strength of ≈ 900 MPa and a conductivity of 70% IACS can be formed.

Highlights

Low-alloy dispersion-hardened copper alloys of the CuCr-Zr system have a high electrical and thermal conductivity [1, 2]
That as a result of severe plastic deformation (SPD) performed by equal channel angular pressing (ECAP) a microstructure with an average grain size of 250-300 nm is formed in Cu-CrZr alloys
As a result of the high pressure torsion (HPT), a high-strength UFG state with a grain size of 140 nm was formed in the Cu-Cr-Zr alloy

Summary

Introduction

Low-alloy dispersion-hardened copper alloys of the CuCr-Zr system have a high electrical and thermal conductivity [1, 2]. The introduction of a small addition of zirconium leads to an increase in strength properties, and to a significant improvement in ductility at elevated temperatures Alloys of this system are traditionally used in applications where a combination of high mechanical strength, heat resistance and electrical conductivity for manufacturing of contact wires, spot welding electrodes, fusion reactors, etc. The combination of SPD and subsequent aging seems to be a promising direction for the simultaneous formation of high strength and electrical conductivity in the alloys of the Cu-Cr-Zr system. It worse to note, that as a result of SPD performed by equal channel angular pressing (ECAP) a microstructure with an average grain size of 250-300 nm is formed in Cu-CrZr alloys. We investigated the effect of the strain degree which was 2 times greater than in [14] on the strength and electro conductivity of the Cu-0.5Cr-0.2Zr alloy

Experimental

Results and discussion

Conclusions