Investigation on the dual-phase co-deformation behavior and strengthening mechanism in cold-drawn Cu–20Fe alloy

In this work, cold drawing deformation was applied aiming to achieve a good combination of strength and electrical conductivity of Cu–20Fe alloy, and also such underlying mechanisms for microstructure evolution and strengthening, as well as variation in conductivity were clarified. It is also found that both Cu matrix grains and Fe-rich dendrites can be significantly refined and transformed into fibrous structure with increasing of drawing strain. The average size of Cu grains and thickness of Fe fiber are 0.47 ± 0.05 μm and 25 ± 5 nm, respectively for alloy subjected to the drawing strain of η = 5.78. In addition, the Fe dendrites exhibit a strong <110> fiber texture, while the corresponding Cu matrix forms a <111> fiber texture. It is demonstrated that the excellent properties with the yield strength of 1173 MPa and the electrical conductivity of 41 %IACS can be reached for cold-drawn Cu–20Fe alloy. In addition, the quantitative analysis on strengthening contributions shows that the high strength of as-drawn Cu–20Fe alloy is dominantly originated from high-density Fe fibers. Meanwhile, the lower electrical conductivity is ascribed to the high solute Fe content and high-density Cu/Fe heterogeneous phase interface.