Grain-boundary precipitation architected hard-shell heterostructure achieves extraordinary strain hardening in high-entropy alloys

TY - JOUR

T1 - Grain-boundary precipitation architected hard-shell heterostructure achieves extraordinary strain hardening in high-entropy alloys

AU - Wang, Liang

AU - Lu, Wenjun

AU - Wang, Xutao

AU - Wang, Linjing

AU - Guo, Wenqi

AU - Liang, Yaojian

AU - Jin, Ke

AU - Wang, Benpeng

AU - Li, Yunkai

AU - Ren, Yang

AU - Wu, Xiaolei

AU - Xue, Yunfei

N1 - Publisher Copyright: © 2026 Acta Materialia Inc.

PY - 2026/5/15

Y1 - 2026/5/15

N2 - Grain-boundary (GB) precipitation can significantly reduce GB cohesion and promote stress concentration, usually leading to catastrophic intergranular embrittlement. Conventional strategies typically focus on suppressing GB precipitation to mitigate these adverse effects. Here, we report that GB precipitation can be turned into an advantage for the mechanical properties of alloys. Specifically, we constructed a core-shell heterostructure (CSH) in high-entropy alloys (HEAs). The face-centered-cubic FCC/L12 matrices in the grain interior serve as ductile cores, while discontinuous body-centered-cubic (BCC) lamellae precipitate at the GBs to form hard shells. The CSH characteristic can induce significant hetero-deformation in the cores, improving the strain-hardening rate of the alloys. Moreover, the FCC/L12 phases permeate the spaces among the discontinuous BCC lamellae and act as plastic-deformation channels for the hard shells, achieving the coordinated deformation of the grains on both sides of the shells and reducing stress concentration. Finally, CSH exhibits an extremely high strain-hardening rate (∼4 GPa) during uniform deformation, together with a high yield strength (∼1 GPa), and still considerable ductility (∼30%). Our work showcases a strategy that turns the otherwise undesirable GB precipitation to our advantage for achieving an unusual synergy of strain-hardening, strength, and ductility in alloys.

AB - Grain-boundary (GB) precipitation can significantly reduce GB cohesion and promote stress concentration, usually leading to catastrophic intergranular embrittlement. Conventional strategies typically focus on suppressing GB precipitation to mitigate these adverse effects. Here, we report that GB precipitation can be turned into an advantage for the mechanical properties of alloys. Specifically, we constructed a core-shell heterostructure (CSH) in high-entropy alloys (HEAs). The face-centered-cubic FCC/L12 matrices in the grain interior serve as ductile cores, while discontinuous body-centered-cubic (BCC) lamellae precipitate at the GBs to form hard shells. The CSH characteristic can induce significant hetero-deformation in the cores, improving the strain-hardening rate of the alloys. Moreover, the FCC/L12 phases permeate the spaces among the discontinuous BCC lamellae and act as plastic-deformation channels for the hard shells, achieving the coordinated deformation of the grains on both sides of the shells and reducing stress concentration. Finally, CSH exhibits an extremely high strain-hardening rate (∼4 GPa) during uniform deformation, together with a high yield strength (∼1 GPa), and still considerable ductility (∼30%). Our work showcases a strategy that turns the otherwise undesirable GB precipitation to our advantage for achieving an unusual synergy of strain-hardening, strength, and ductility in alloys.

KW - Core-shell heterostructure

KW - Grain-boundary precipitation

KW - Hetero-deformation

KW - High-entropy alloys

KW - Strain hardening

UR - https://www.scopus.com/pages/publications/105033571917

U2 - 10.1016/j.actamat.2026.122151

DO - 10.1016/j.actamat.2026.122151

M3 - Article

AN - SCOPUS:105033571917

SN - 1359-6454

VL - 310

JO - Acta Materialia

JF - Acta Materialia

M1 - 122151

ER -