Effects of solute, temperature and strain on the electrical resistivity of Cu–Ag filamentary composites

Abstract

The filamentary composites of Cu–6 wt%Ag, Cu–6 wt%Ag–0.2 wt%Zr and Cu–24 wt%Ag were prepared by heavy drawing. The electrical resistivity at various temperatures and draw ratios was determined in order to investigate the effects of the solute concentration, measured temperature and strain level on the electrical conductivity. The conductivity of all tested composites, especially for Cu–6 wt%Ag, decreases with the temperature increasing from 77 to 293 K. Minor constituent Zr or high Ag content in the filamentary composites significantly impairs the conductivity at temperatures lower than 293 K. The resistivity at 77–293 K slightly increases but at 373–573 K slightly decreases with the draw ratio increasing from 6.1 to 9.4 for Cu–6 wt%Ag. Additional solute atoms, large interfacial area and high dislocation density in Cu–6 wt% Ag–0.2 wt%Zr and Cu–24 wt%Ag are mainly responsible for the conductivity reduction. Dislocation scattering and interface scattering mainly affect the resistivity at low temperatures. Phonon scattering mainly affects the resistivity at high temperatures.