Influences of different prior heat treatments on the microstructural and mechanical properties of Cu–Fe filamentary composites

Cu–6 wt.% Fe and Cu–12 wt.% Fe filamentary composites were prepared by casting and cold drawing. And a different heat treatment of quenching and aging or homogenizing was introduced before cold drawing process, respectively. The microstructure was observed and the tensile strength measured for the composites at different drawing strains. The quenching and aging or homogenizing prior to drawing deformation refine the as-cast microstructure and result in the increase in interface density in the drawn microstructure. The drawn alloys with the homogenizing treatment show smaller filament spacing than those with the quenching and aging treatment because homogenizing results in smaller and more dispersive primary Fe dendrites before drawing deformation. The heat treatments can improve the strength of the composites by increasing precipitation strengthening and interface strengthening levels. With the reduction in filament spacing during drawing deformation, the strength of the alloys with smaller initial size of Fe dendrites increases more obviously.

► Cu–Fe composites prepared by introducing different prior heat treatments.
► As-cast structure refined and precipitation of secondary Fe particles promoted.
► Interface density increased and strength improved.
► Fe dendrites initial size is smaller, strength increases more obviously.