Beyond elemental intrinsic characteristics: ΔHmixB−F-driven solid solution phase structure modeling in HEAs

Abstract

This study introduces an innovative approach for predicting solid-solution phase structures in high-entropy alloys (HEAs) by integrating a thermodynamic mixing enthalpy difference parameter $\Delta H_{\text{mix}}^{B-F}$—quantifying inter-element interactions between BCC and FCC structures—with conventional descriptors representing elemental intrinsic properties, including valence electron concentration (VEC), atomic size mismatch (δ), and Gibbs free energy differences of pure elements in dual-phase configurations ($\Delta G_0$). This synergistic framework significantly enhances the predictive accuracy for solid solution phase structures in HEAs, achieving a classification consistency rate (CCR) of 94.9 % across 569 HEA systems through the combined VEC+ $\Delta H_{\text{mix}}^{B-F}$ parameter. To validate the methodology, a series of unreported transition-metal-rich AlCoCrNiV-based HEAs were synthesized and systematically characterized via X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) coupled with energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) with microchemical analysis. The experimental observations exhibit excellent agreement between the predicted phase constitutions and the observed structural features, demonstrating the reliability and practical applicability of the proposed strategy. This work establishes a robust foundation for rational HEA design and provides critical guidance for advancing predictive frameworks in multi-component alloy systems through the integration of thermodynamic principles and empirical descriptors.