Effect of Ce addition on microstructure evolution and precipitation in Cu-Co-Si-Ti alloy during hot deformation

Abstract

Abstract Hot compression behavior of the Cu–Co–Si and Cu–Co–Si–Ti alloys was studied using the Gleeble-1500 simulator at 0.001–10 s−1 strain rate and 500–900 °C deformation temperature. Ti addition increased the flow stress of the Cu–Co–Si–Ti alloy compared with the Cu–Co–Si alloy at the same deformation conditions. With the deformation temperature increased from 700 °C to 900 °C, the Cu–Co–Si alloy texture transformed from the copper texture to the R texture. Due to the addition of Ti, the copper texture and R texture were substituted by the Goss texture and the copper texture, respectively. The constitutive models of the Cu–Co–Si and Cu–Co–Si–Ti alloys hot deformation behavior were obtained. The activation energy of the Cu–Co–Si alloy was 411.648 kJ/mol, and the activation energy of the Cu–Co–Si–Ti alloy was 500.794 kJ/mol, which is 27% higher. The precipitated Co2Si phase was found in both Cu–Co–Si and Cu–Co–Si–Ti alloys deformed at 700 °C and 0.001 s−1. In addition, the CoSi and Cu4Ti phases were found in the Cu–Co–Si and Cu–Co–Si–Ti alloys, respectively. The strengthening mechanisms, including dispersion strengthening, twinning and grain refinement strengthening, control the Cu–Co–Si–Ti alloy hot deformation, and lead to increased flow stress and activation energy, and inhibit dynamic recrystallization of the Cu–Co–Si–Ti alloy.