Thermomechanical Treatment Behavior and Aging Precipitation Mechanism of Cu-7Fe-0.3Mg Alloy

Proper thermomechanical treatment can enhance the comprehensive performance of Cu-Fe alloys. This research delves into the microstructure and properties of Cu-7Fe-0.3Mg alloy to uncover the microstructure evolution and the aging precipitation mechanism throughout thermomechanical treatment. The as-cast Cu-7Fe-0.3Mg alloy exhibits a predominance of spherical, as well as some branching dendritic, iron-enriched regions. Following plastic deformation, the Fe-rich phases are fragmented and elongated into rod-like shapes along the rolling direction. Throughout the aging treatment, the alloy contains two distinct precipitate sizes. As the time and temperature of the aging treatment increase, the quantity of precipitates increases, while the concentration of dislocations density diminishes. At the peak aging conditions of 460 degrees C for 8 hours, the precipitates are uniformly distributed across the alloy, primarily ranging in dimensions from 10 to 25 nm. Further increases in aging time and temperature lead to significant coarsening of precipitates and clustering phenomena. After peak aging treatment, the alloy exhibits excellent comprehensive performance, with electrical conductivity, microhardness, and tensile strength reaching 59.67% IACS, 200.23 HV, and 553.27 MPa, respectively. The strengthening and electrical conduction mechanisms suggest that the precipitation of Fe-rich phases is pivotal in enhancing the comprehensive performance.