Effect of Al addition on Fe phase morphology and alloy properties of Cu-5Fe alloys

The effects of Al addition on the organization and properties of Cu-5Fe alloys were investigated by using transmission electron microscopy, backscattered electron diffractometer and tensile testing machine combined with first principle calculations, and the evolution laws of Fe phase morphology, aging kinetics and properties were systematically explored. The results show that the addition of Al significantly refines the Fe phase, suppresses the dendritic segregation, and improves the tensile strength of the Cu-5Fe alloy, and Considering the optimal composition alloy is -0.2 Al alloy,Cu-5Fe-0.2Al alloy are 656.5 MPa and 60.8% IACS, respectively, which increased the tensile strength by about 190 MPa compared with that of the Cu-Fe alloy. In addition, the Al addition reduced the activation energy of precipitation of the Fe phase by 5.42 kJ/mol, which facilitated the precipitation of the Fe phase, and thus enhanced the particle density of the Fe nanoparticles. The doping of Al significantly improved the shear strength, hardness, and thermal stability of the Cu-Fe alloys through the formation of strong Al-Cu bonds and optimization of the charge distribution. By forming strong Al-Cu bonds and optimizing the charge distribution, Al doping significantly improves the shear strength, hardness, and thermal stability of Cu-Fe alloys, while significantly reducing the anisotropy, which is the main reason for the more uniform distribution of Fe phases and the substantial improvement of the mechanical properties of Cu-Fe-Al alloys.