Effect of alloying elements on properties of deformation-processed Cu-Fe in situ composites

Effect of doping with a little of Zr, Mg and the content of Fe on the microstructure, electrical resistivity and strength of deformation-processed Cu-Fe in situ composites were studied on resistance measuring apparatus, material test system (MTS), scanning electron microscope (SEM) and transmission electronic microscope (TEM). The results show that with the addition of Zr, the ultimate tensile strength (UTS) of the Cu-Fe alloys increases by 10%, whereas its electrical conductivity does not decrease markedly. The electrical resistivity of Cu-Fe in situ composites slightly decreases with increasing annealing temperature to 400°C, then increases rapidly. UTS of the composites increase slightly with increasing annealing temperature to 150°C, and above 300°C the UTS decreases. Thermal stability of Cu-Fe composites is improved with doping Zr. The strength of Cu-Fe dropped more rapidly at higher annealing temperatures (above 400°C ) than that of Cu-Fe-Zr. Doping with Mg results in the embrittlement of Cu-Fe composites. The electrical resistivity and the strength of these composites increase with the increasing of deformation strain and iron content. The tensile strength and electrical conductivity are improved by annealing at 150°C for 2 h and at 300°C for 2 h.