Study on the microstructure evolution and mechanical properties of spray-forming Cu-Fe alloys with varying Fe compositions

In this research, Cu-Fe alloys with Fe compositions of 5, 10, 20, and 30 % were successfully fabricated using a novel spray-forming method and followed by cold rolling. The impacts of varying Fe compositions on solidification behavior, microstructure evolution, and mechanical characteristics were systematically investigated using various analytical methods, including OM, EPMA, XRD, SEM, EBSD, and TEM. The findings demonstrate that the Fe particles of the spray-formed Cu-Fe alloys with all components exhibit a fine and uniform distribution within the Cu matrix. With the increase in Fe compositions, the average grain diameter of the Cu matrix is obviously refined. The deformation behavior and the reinforcement mechanisms of Cu-Fe alloys with different Fe compositions during cold rolling were also explored. After cold rolling, Cu grains and Fe grains were distinctly refined and stretched into fibers in the rolling direction. The extent of Fe fibers became more pronounced as the Fe composition. The Cu matrix formed strong copper and brass textures. The strength of the spray-formed Cu-Fe alloy after cold rolling increased as the Fe composition increased. The enhanced strengthening effect of the alloy is predominantly attributable to a synergistic combination of high dislocation density within the Cu matrix, grain refinement, and Fe grain fibrillation. Furthermore, the strengthening mechanism of the spray-forming Cu-Fe alloy after cold rolling aligns with the Hall-Petch relationship. The research lays a solid foundation for the preparation and industrial production of Cu-Fe alloys with high Fe compositions.