Effects of thermo-mechanical processing and trace amount of carbon addition on tensile properties of Cu-2.5Fe-0.1P alloys

The effects of thermo-mechanical processing, including intermediate aging treatment and/or solution heat treatment, and a trace amount of carbon (C) addition were studied on tensile behavior of Cu-2.5Fe-0.1P alloys. In this study, Cu-2.5Fe-0.1P alloy sheets without and with a carbon content of 0.05 wt.% were cast and subsequently rolled and thermo-mechanically treated following various processing routes. The introduction of intermediate aging treatment between cold rolling improved the tensile strength of Cu-2.5Fe-0.1P alloys. Solution heat treatment prior to aging was proved to be detrimental on the tensile strength, probably due to recovery and recrystallization causing the complete loss of work hardening during previous cold rolling. The present study also suggested that two-step aging is more effective in improving the strength of Cu-2.5Fe-0.1P alloys than one-step aging. The effect of C addition on improving the tensile strength of Cu-2.5Fe-0.1P alloys was real but marginal, probably due to the limited solubility of C in Cu-2.5Fe matrix. The effects of intermediate heat treatments between cold-rolling processes on tensile properties of Cu-2.5Fe-0.1P specimens with and without C addition are discussed based on optical, scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs, and SEM fractographs.