Nanoindentation into a dual-phase bicontinuous lamellar high-entropy alloy
Abstract
The plastic response of a dual-phase high-entropy alloy to nanoindentation is studied using molecular dynamics simulation. The sample has a bicontinuous lamellar structure consisting of an equiatomic FeNiCrCo fcc phase and an Al 50 (FeNiCrCo) 50 bcc/B2 phase. Its large size ( 28 million atoms) allows comparison of indentations into a fcc lamella, a bcc lamella and on an fcc/bcc interface. In addition, the lamella thickness of 20–30 nm allows for extensive dislocation plasticity both in the fcc and the bcc phase. We find that the hardness of the alloy at the interphase boundary is not a simple average of the hardness of the lamellae. The plasticity is mostly dislocation controlled, and twinning is relevant only in the fcc phase. Phase transformations do not occur and – in contrast to previous studies – even amorphization is negligible. Dislocation pile-ups are observed in the fcc phase next to the interface. Shear strain is not easily transmitted – in the form of dislocations or stacking faults – across phase boundaries.
Related
- Changes in microstructure and phonon thermal conductivity in a lamellar dual-phase high-entropy alloy under tensile strain
- In-Situ TEM Observation of Solid-State Phase Evolution in High-Entropy Alloy Nanoparticles
- Computing binary alloy phase diagrams with explicit configurational and vibrational entropy
- Mechanical behavior of a gradient short range order high entropy alloy
- Temperature effects on the strength of a nanocrystalline refractory high entropy alloy
BibTeX
@article{alhafez2026nanoindentation,
title = {{Nanoindentation into a dual-phase bicontinuous lamellar high-entropy alloy}},
author = {Iyad Alabd Alhafez and Orlando Deluigi and Diego Tramontina and Felipe Valencia and Nina Merkert and Alfredo Caro and Herbert Urbassek and Eduardo Bringa},
journal = {Journal of Materials Research and Technology},
year = {2026},
month = oct,
doi = {10.1016/j.jmrt.2025.05.257},
url = {https://hal.science/hal-05778810v1},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Nanoindentation into a dual-phase bicontinuous lamellar high-entropy alloy
AU - Iyad Alabd Alhafez
AU - Orlando Deluigi
AU - Diego Tramontina
AU - Felipe Valencia
AU - Nina Merkert
AU - Alfredo Caro
AU - Herbert Urbassek
AU - Eduardo Bringa
PY - 2026
DA - 2026/10/05
JO - Journal of Materials Research and Technology
DO - 10.1016/j.jmrt.2025.05.257
UR - https://hal.science/hal-05778810v1
AB - The plastic response of a dual-phase high-entropy alloy to nanoindentation is studied using molecular dynamics simulation. The sample has a bicontinuous lamellar structure consisting of an equiatomic FeNiCrCo fcc phase and an Al 50 (FeNiCrCo) 50 bcc/B2 phase. Its large size ( 28 million atoms) allows comparison of indentations into a fcc lamella, a bcc lamella and on an fcc/bcc interface. In addition, the lamella thickness of 20–30 nm allows for extensive dislocation plasticity both in the fcc and the bcc phase. We find that the hardness of the alloy at the interphase boundary is not a simple average of the hardness of the lamellae. The plasticity is mostly dislocation controlled, and twinning is relevant only in the fcc phase. Phase transformations do not occur and – in contrast to previous studies – even amorphization is negligible. Dislocation pile-ups are observed in the fcc phase next to the interface. Shear strain is not easily transmitted – in the form of dislocations or stacking faults – across phase boundaries.
SN - 2238-7854
SN - 2214-0697
ER -