Static recrystallization and texture evolution of cold-rolled powder metallurgy CoCrFeNiN0.07 high-entropy alloy

Abstract

Static recrystallization and texture evolution of the 80% cold-rolled (CR) powder metallurgy (PM) CoCrFeNiN0.07 high-entropy alloy (HEA) during isothermal annealing were studied. The results show that the CR sheet exhibit a large number of shear bands, severe elongated grains and weak combination of α-fiber, γ-fiber and τ-fiber texture. The static recrystallization temperature of the CR sheet is 700 °C. The recrystallization activation energy is 232.7 kJ mol−1 following the Arrhenius-type relation. When the annealing temperature increase from 750 °C to 950 °C, the average recrystallization grain size increases from 635 nm to 2.7 µm, and the yield strength (YS) reduced from 712 MPa to 572 MPa, ultimate tensile strength (UTS) reduced from 981 MPa to 910 MPa, the elongation (EL) increased from 43% to 57%. Due to high dependence of recrystallization grain orientation on parent crystal, the {111}<112>F texture retained in recrystallized grains during annealing, but with the increase of recrystallization temperature, the recrystallization texture tends to be weak and scattered.