Influence of alloying on thermodynamic properties of AlCoCrFeNiTi high entropy alloys from DFT calculations

Abstract

High entropy alloys (HEAs) represent a class of structural materials with a number of very promising properties; however, most of them are not investigated in detail and therefore are not so well–developed as other classical materials such as steels or Ni-base alloys. Knowledge-based design and development of novel HEAs requires predictive computational methods capable of accurate predictions of the alloy properties as most of them are not so well experimentally investigated as other classical materials. In this work, we present the results of a density functional theory (DFT) study on thermodynamic properties of a series of non–equimolar paramagnetic fcc AlCoCrFeNiTi HEAs. The results of the DFT calculations are used in model calculations taking into account not only electronic but also magnetic and phonon degrees of freedom to evaluate thermodynamic properties of HEAs at the room temperature. The calculated data show good agreement with the results of the X-ray diffraction analysis of the lattice constants of two selected HEAs and provide new insights into the compositional design of paramagnetic fcc HEA.