Pressure- and temperature-dependent physical metallurgy in a face-centered cubic NiCoFeCrMn high entropy alloy and its subsystems

The pressure and temperature dependence on the physical properties of medium and high entropy alloys is an intriguing topic in materials science and its different technological applications. In this study, the structural, elastic, mechanical, electronic, and thermal properties of Ni-based alloys are investigated by abinitio molecular dynamics (AIMD) calculations and molecular dynamics (MD) simulations. First, the elastic, electronic, and mechanical properties of the Ni-based alloys are calculated; these include the bulk, shear, and Young's moduli, the anisotropy factor, Poisson's ratio, Pugh's ratio, and the hardness. Next, the effects of temperature and pressure on the structural, elastic, mechanical, and electronic characteristics of Ni-based high entropy alloy and its subsystems are analyzed. In all cases, the 3d states have the dominant contributions to the electronic dispersion near the Fermi level. We have also investigated the lattice dynamical properties and found that the materials under consideration are dynamically stable. NiCoFeCrMn has the highest entropy among these alloys and subsystems. Moreover, it has a low thermal expansion coefficient, suggesting that it is suitable for high-temperature applications. Our simulation results unambiguously show the significance of considering the influence of temperature and pressure on the physical properties of Ni-based alloys for their high temperature and pressure applications. (c) 2021 Elsevier B.V. All rights reserved.