High temperature deformation behavior and dynamic recrystallization in CoCrFeNiMn high entropy alloy

Microstructure evolution in high-entropy alloy CoCrFeNiMn during uniaxial compression to a height reduction of true strain of ≈1.4 in the temperature interval 600–1100 °C was studied. Although some differences was observed in the mechanical behavior of the alloy and the activation energy of deformation in warm (below 800 °C) and hot (above 800 °C) temperature intervals, microstructure evolution at all studied temperatures was found to be accompanied by discontinuous dynamic recrystallization (dDRX). During hot deformation recrystallization was primary associated with nucleation of new grains on the initial grain boundaries, while in the warm interval dDRX was mainly observed in shear bands. The volume fraction of the recrystallized structure was respectively 0.085 and 0.95 at 600 and 1000 °C and the recrystallized grain size was found to be 0.2 and 40.4 µm for 600 and 1100 °C, respectively.