Unified Model for the Solution of Interstitials in Refractory High-Entropy Alloys

Area of Science:

• Materials Science
• Solid State Chemistry
• Computational Materials Science

Background:

• Interstitial nonmetallic solutes (INSs) like H, He, O, C, N, P, and S are prevalent in refractory high-entropy alloys (RHEAs).
• The properties of RHEAs are significantly influenced by the dissolution of these INSs.
• The complex local chemical environments in RHEAs complicate the prediction of INS stability and mechanistic understanding.

Purpose of the Study:

• To develop a predictive analytic model for determining the solution energy of INSs in RHEAs.
• To provide an electronic-level understanding of INS behavior in RHEAs.
• To facilitate the rational design of advanced RHEAs.

Main Methods:

• Utilized tight-binding models as the foundation for the proposed analytic model.
• Developed a scheme to quantitatively predict the solution energy of INSs.
• Analyzed the linear dependence of INS energetics on the d-band width of neighboring atoms.

Main Results:

• Established a linear relationship between the energetics of INSs and the d-band width of their neighboring elements.
• Identified that the slope of this linear relationship is dictated by the bonding characteristics of the INSs.
• The model successfully explains key experimental observations regarding INS behavior in RHEAs.

Conclusions:

• The proposed analytic model offers an electronic-level understanding of INS solution in RHEAs.
• This predictive tool can guide the design of novel RHEAs with enhanced properties.
• The model simplifies the prediction of INS stability in complex alloy systems.