Tailoring discontinuous precipitation in Cu-3.2Ti-0.3Nb alloy for enhanced mechanical and electrical properties

This study introduces 0.3 wt.% Nb into a Cu–3.2Ti alloy to promote discontinuous precipitation (DP). The effect of DP on the microstructural evolution and comprehensive properties of the alloy under different thermo-mechanical processing routes was systematically examined. The results show that after aging at 525 °C for 20 h followed by 90% cold rolling, the Cu–3.2Ti–0.3Nb alloy achieves an optimal property combination: a tensile strength of 1062 MPa, an electrical conductivity of 22.1 % IACS, and an elongation of 10%. With increasing cold rolling deformation, the DP structures are notably refined and their morphology changes from lamellar to fibrous. This fibrous transition significantly contributes to the enhancement of the alloy’s strength. Analysis of the strengthening mechanisms indicates that the strength is mainly derived from dislocation strengthening, grain boundary strengthening, and precipitation strengthening. The findings demonstrate that controlling DP morphology through deformation is an effective strategy for achieving an attractive strength–conductivity balance in Cu–Ti based alloys.