Microstructure evolution of graphene reinforced Cu/CeO2/Cr electrical contact materials under thermal deformation behavior

The effect of graphene on the thermal deformation of Cu/CeO2/Cr and GO-Cu/CeO2/Cr composites was studied. The isothermal compression test was carried out with Gleeble-1500D thermomechanical simulation device in the range of 600–900 °C and strain rate of 0.001–1 s−1. The microstructure after deformation was characterized and analyzed by optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM) and electron backscatter diffraction (EBSD). The interaction of work hardening, dynamic recovery and dynamic recrystallization was described. The constitutive equation was successfully established. The results show that Cr particles are extruded into strips, and nano CeO2 particles nail dislocations, which inhibit dynamic recovery and dynamic recrystallization. Dispersion strengthening, twin strengthening and grain refinement strengthening occur the thermal deformation of GO-Cu/CeO2/Cr composites, increase the flow stress and activation energy of the composites, and inhibit the dynamic recrystallization of the composites. When the hot deformation temperature increases, the texture orientation is strengthened. GO-Cu/CeO2/Cr composites have typical dynamic recovery characteristics and high temperature properties.