Effect of Fe Content on the Microstructure and Mechanical and Electrical Properties of Cu-Fe In Situ Composites

Cu-Fe in situ composites with different Fe contents were prepared by casting and cold drawing deformation. The microstructure was observed, and the mechanical and electrical properties were measured during the deformation process. The composites with a higher Fe content show a higher strength but a lower electrical conductivity because the Fe content is high enough to produce sufficient dendrite structures, resulting in strengthening and electronic scattering effects. The strain hardening of the Cu matrix mainly results in the strengthening of Cu-3 wt.% Fe. The strengthening of Cu-6 wt.% Fe is mainly attributed to the strain hardening of the Cu matrix at a lower draw ratio and the increased interface density at a higher draw ratio. A larger amount of Fe precipitates and a higher interface density lead to an improvement in the strength of Cu-12 wt.% Fe. The conductivities of the Cu-3 wt.% Fe and Cu-6 wt.% Fe alloys are similar due to the continuous Cu matrix or similar electron transmission in the Cu matrix, while that of Cu-12 wt.% Fe is much lower due to the smaller dendrite spacing and the larger amount of Fe precipitates.