Microstructure and properties of Cu–Fe microcomposites with prior homogenizing treatments

Abstract

Cu–6 wt.% Fe and Cu–12 wt.% Fe microcomposites were prepared by cold drawing. A homogenizing treatment at 950 °C for 3 h followed by furnace cooling was carried out before drawing. The microstructure was observed and the tensile strength and electrical resistivity were determined. The original cast or homogenized microstructure develops into the filamentary composite structure in drawing process. The homogenizing treatment promotes the precipitation of secondary Fe particles in the Cu matrix and disperses primary Fe dendrites. Fe precipitates and dispersive Fe dendrites in the homogenized microstructure result in finer and more uniform composite filaments in the drawn microstructure. The tensile strength and electrical resistivity increase with the increase in drawing strain. The homogenizing treatment increases the strength, especially for the microcomposites at high draw ratios and decreases the resistivity, especially for Cu–6 wt.% Fe. The improvements in strength and conductivity as a result of the prior homogenizing treatment can be attributed to the increased interface obstacle and reduced solute scattering in the filamentary structure.