Tailoring the microstructure and properties of Cu-15Fe rolling-deformation alloy by yttrium micro-alloying

The synergistic effects of yttrium micro-alloying and heavy strain rolling deformation on the micro -structure and properties of Cu-15Fe alloy were investigated systematically in this work. The results indicate that trace yttrium element is beneficial to refine the Fe phase structure of Cu-15Fe alloys and reduce the distance between Fe fibers after rolling, which stimulates different strengthening mechanisms to optimize the mechanical properties of the alloy. The appropriate amount of yttrium atom in solution can promote the refinement of primary Fe phase and the precipitation of Fe particles, which can cooperatively improve the mechanical-electrical properties and high temperature anti-intenerate properties of the alloy. However, the excess yttrium element forms a network distribution of intermetallic compounds at grain boundaries, which reduces the overall performance of the alloy. When yttrium content is 2 x 102 ppm level, the comprehensive performance of Cu-15Fe alloy strip can achieve 706.9 MPa/198.1 HV/41.3%IACS. Moreover, the synergistic effect of rolling deformation and aging treatment can effectively reduce the interfacial energy of the alloy, decrease the interfacial scattering and promote the precipitation of Fe particles, which can optimize the electrical and mechanical properties of Cu-15Fe-Y alloy. The conductivity of yttrium micro-alloyed Cu-15Fe alloy strips was significantly improved to 56%IACS with aging treatment at 500 celciusx 120 min.