Expansion of thermodynamic calculation principle of multi-component alloy and its application in the study of thermodynamic properties of the Cr–Mo–Nb–V high entropy alloy

In this paper, based on the improved Miedema model and the quaternary alloy calculation model expanded by Chou model, the activity calculation model of the ternary alloy system is extended to the quaternary alloy system through the ternary alloy activity calculation model of Wagner and Ma Zhongting et al. In addition, a new deviation function is used in the expanded quaternary alloy calculation model to calculate the thermodynamic properties of quaternary alloys, which meets the characteristics of both non-negativity and reducibility. Using the developed model, this paper calculates the thermodynamic data of each sub-binary, sub-ternary, and quaternary system in the Cr–Mo–Nb–V quaternary high entropy alloy system. Subsequently, this paper analyzes the interactions between components, predicts the possible precipitated phases in the alloy system, and explains the possibility of forming a solid solution in the alloy system. The final results are consistent with those shown in the literatures on studying the Cr–Mo–Nb–V quaternary alloy system, which verifies the applicability of the developed model in the miscible alloy system, enriches the thermodynamic database of Cr–Mo–Nb–V alloy, and provides theoretical reference and ideas for the design of multi-component alloys. [Display omitted] •We analyzed interaction, solid solution formation, and precipitates in Cr-Mo-Nb-V alloy using quaternary alloy calculations.•A new deviation function for quaternary alloy thermodynamics was developed, ensuring non-negativity and reducibility.•We derived an activity model for quaternary alloys based on Wagner and Ma Zhongting's ternary alloy activity model.