Significance of local atomic intermixing for interphase hardening

Clarify the significance of local atomic intermixing near the interphase boundaries of the HPT-processed Al0.1CoCrFeNi + TiZrHfNbTa nanolamellar hybrid high-entropy alloy for interphase hardening through interface-specific mechanical testing or atomistic simulation.

Background

The paper estimates that approximately 30% of the hybrid alloy’s hardness enhancement beyond Hall–Petch and defect-induced hardening originates from its nanolamellar structure. However, the authors emphasize that this value is an estimate based on a rule-of-mixtures analysis rather than a direct measurement. They identify local atomic intermixing near the BCC/FCC interphase boundaries as a factor that may influence interphase hardening, but its quantitative significance has not been established.

The unresolved issue is proposed for investigation using interface-specific mechanical testing or atomistic simulation, which could separate the effects of interphase structure, coherency, localized intermixing, and related interface-controlled strengthening mechanisms.

References

The local atomic intermixing near interphase boundaries (Fig. 6b) can potentially affect the interphase hardening phenomenon, although clarification of the significance of this effect remains a subject for future interface-specific mechanical testing or atomistic simulation.

— Nanolamellar Hybrid High-Entropy Alloys with Superior Micromechanical Properties  (2608.28268 - Dangwal et al., 28 Aug 2026) in Discussion, paragraph beginning “A full quantitative separation of the interphase, grain-boundary and defect contributions”