Influence of cold rolling and annealing on the microstructure, mechanical properties, and electrical conductivity of an artificial microcomposite Cu-18% Nb alloy

The influence of cold rolling and subsequent annealing at different temperatures on the micro-structure, strength properties, and electrical conductivity of a microcomposite Cu-18% Nb alloy fabricated by bundling and deformation is studied. A composite billet is rolled up to a total true strain of 3.5 and 5.1. After rolling, a nanocrystalline structure is obtained with an average filament width of 70-100 nm depending on the rolling strain. The ultimate tensile strength of the rolled foils is 867-934 MPa and the electrical conductivity is 19-40% of the pure copper conductivity. It is shown that annealing at 550°C results in an increase in the conductivity from 40 to 60% at a retained strength (microhardness) of the alloy. © 2010 Pleiades Publishing, Ltd.