Development of ultrahigh strength novel Co–Cr–Fe–Ni–Zr quasi-peritectic high entropy alloy by an integrated approach using experiment and simulation

Abstract

For the first time, we report here that (CoCrFeNi)90Zr10 bimodal eutectics high entropy alloy (HEA) consisting of both globular eutectics (i.e., L ⟶ FCC (α) + Ni2Zr-type Laves phases) and lamellar eutectics (i.e., L ⟶FCC (α) + Ni7Zr2) is designed and developed by an integrated approach of using thermodynamic simulation and experimental techniques. The present study explores the understanding of new pseudo-quasiperitectic four-phases equilibrium reaction, i.e., L + Ni2Zr⟶FCC (α)+ Ni7Zr2 in the novel (CoCrFeNi)90Zr10 quasi-peritectic HEA (QHEA). The hot deformation behavior of QHEA has been investigated in the temperature range 1073–1323 K and different strain rates (10−3,10−1,1and 10 s−1). Arrhenius-type constitutive equation and artificial neural network (ANN) model have been used to predict the flow stress of QHEA during thermomechanical processing. The hot workability regimes of QHEA has been identified using multiple model parameters, indicating stable regimes in temperature range 1073–1323K and strain rate range 10−3–10−1.3 s−1 as well as temperature range 1073–1125 K and strain rate range10−3–10−0.75 s−1. The plastic strain field distribution and material flow behavior during hot deformation of newly developed QHEA have been predicted using Finite element simulation. © 2020