Small Y Addition Effects on Hot Deformation Behavior of Copper‐Matrix Alloys

Hot deformation behavior of two alloys, Cu-Zr and Cu-Zr-Y is studied by compression tests using the Gleeble-1500D thermo-mechanical simulator. Experiments are conducted at 550-900 degrees C temperature and 0.001-10 s(-1) strain rate. The true stress-true strain curves are analyzed, and the results show that the flow stress strongly depends on the temperature and the strain rate. Furthermore, both alloys behave similarly when the flow stress increases with higher strain rate and lower temperature. Based on the dynamic material model, the processing maps are obtained at strains of 0.4 and 0.5. The optimal processing parameters for the Cu-Zr and Cu-Zr-Y alloys are determined. In addition, the constitutive equations for the alloys are established to characterize the flow stress as a function of strain rate and deformation temperature. Based on the microstructure evolution analysis, the results show that the addition of Y can effectively promote dynamic recrystallization. Moreover, the processability of the alloy can be optimized. Thermal deformation activation energy and the peak power dissipation efficiency for the alloys are obtained. It is observed that the addition of Y effectively improves thermal deformation activation energy and has considerable influence on the peak power dissipation efficiency.