Hot deformation behavior and microstructure characterization of AlCrFe2Ni2(MoNb)0.2 high entropy alloy

Abstract

The hot deformation behavior and microstructure evolution of AlCrFe2Ni2(MoNb)0.2 eutectic high entropy alloy at deformation temperatures of 900 °C–1100 °C and strain rates of 0.001 s−1∼1 s−1 were systematically investigated by hot compression tests. The principal structure equations of AlCrFe2Ni2(MoNb)0.2 high entropy alloy were constructed using the Arrhenius equation modified by Zener-Hollomon parameters. The decrease of strain rate and the increase of deformation temperature can enhance the continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) processes simultaneously. The power dissipation and instability diagrams were constructed according to the power dissipation theory and instability criterion, and the hot processing diagrams with strains of 0.3–0.6 were obtained by combining with the Dynamic Material Model (DMM) theory. According to the analysis of power dissipation rate and processing safety zone, the optimal hot processing parameters were found to be ε = 0.6 for the true strain, T = 1050–1100 °C, ε˙ = 0.0037–0.031 s−1.