Studies of electrical resistivity of an annealed Cu-Fe composite

Cu-15 vol. % Fe composites produced by cold deformation were annealed at various temperatures for 1 h. The electrical resistivity, tensile strength, and microstructure were investigated by four-probe technique, electronic universal testing machine, and scanning electron microscopy (SEM), respectively. The Fe solubility in Cu-matrix was estimated from the saturation magnetization of the composites. The results reveal that the resistivity of impurity scattering ρimp is the main contributor to the resistivity of the Cu-Fe composites if the phonon and dislocation scattering contributions to the electrical resistivity are considered to be constants. At annealing temperatures below 500 °C, an increase of filament spacing and reduction of interface area in unit volume result in a marginal decrease of the resistivity with temperatures. Above 500 °C, the Fe solubility in Cu-matrix rapidly increases with temperature, which directly causes the increase of composites resistivity.