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Practical applications with potential use of eutectic high entropy alloys (EHEAs) involve thermo-mechanical processing. The hot compression behaviors and microstructure evolution of a dual phase AlCoCrFeNi 2.1 EHEA under various thermo-mechanical conditions were investigated. The initial microstructure comprises lamellar FCC/L1 2 (65.5 %) and BCC/B2 (34.5 %) phases, with L1 2 nanoprecipitates (with an average size of 7.9 nm) uniformly dispersed in the dendritic FCC and the B2 particles (with an average size of 35.8 nm) evenly distributed among the BCC phases. The influence of strain rate and temperature on the evolution of the microstructure is revealed. The evolution of microstructure can be interpreted in terms of the interactions between dynamic softening (dynamic recrystallization) and hardening (work hardening). Elevated deformation temperatures (up to 1473 K) and reduced strain rates (0.001 s −1 ) promote dynamic recrystallization grain-coarsening while decreasing dislocation densities. In addition, twin-mediated dynamic recrystallization nucleation was observed at low strain rates (0.001 s −1 ). The Arrhenius mode and Zerilli-Armstrong plastic model were applied to model the dynamic flow behavior of the dual phase AlCoCrFeNi 2.1 , and the constitutive relationship was obtained. These findings provide critical insights for optimizing thermomechanical processing of dual-phase EHEAs in high-temperature structural applications.
Liu et al. (Sat,) studied this question.