Phase transformation within dynamically refined microbands inducing ultrahigh and sustained strain hardening in high-entropy alloys containing L12 precipitates

被引：2

作者：

Li, Hongchao ^{[1
]}

Wang, Jun ^{[2
]}

Zhao, Jiawang ^{[2
]}

Li, Jinshan ^{[2
]}

Fu, M. W. ^{[1
]}

机构：

[1] Hong Kong Polytech Univ, Res Inst Adv Mfg, Dept Mech Engn, Hung Hom, Hong Kong, Peoples R China

[2] Northwestern Polytech Univ, Sch Mat Sci & Engn, State Key Lab Solidificat Proc, Xian 710072, Peoples R China

来源：

ACTA MATERIALIA | 2025年 / 289卷

关键词：

High-entropy alloy; L1; 2; precipitates; Microbands; Phase transformation; Superlattice intrinsic stacking faults; STACKING-FAULT ENERGIES; MECHANICAL-PROPERTIES; DEFORMATION-BEHAVIOR; HIGH-STRENGTH; MARTENSITIC-TRANSFORMATION; INDUCED PLASTICITY; START TEMPERATURE; GRAIN-SIZE; STEEL; DUCTILITY;

D O I：

10.1016/j.actamat.2025.120930

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Metallic materials exhibiting ultrahigh strength coupled with exceptional ductility play a pivotal role in advanced industries, yet enhancing strength typically sacrifices strain hardening and ductility. This study presents a strategy that activated an innovative deformation mechanism to overcome the long-standing trade-off between strength and ductility in an L12-strengthened Al5Ti8(FeCoNi)86.9B0.1 high-entropy alloy. After aging at 765 degrees C for 4 hours, the alloy achieved a yield strength of 1227 MPa, an ultimate tensile strength of 1742 MPa, and an elongation of 39.9%, attributed to the ultrahigh and sustained strain hardening induced by phase transformation within dynamically refined microbands during deformation. Our findings indicated that FCC -> BCC transformation within the microbands was more favorable in an FCC matrix with a larger width. Furthermore, a high density of superlattice intrinsic stacking faults and Lomer-Cottrell locks in L12 phase were formed, leading to additional strain hardening of the alloy. The synergistic interaction between phase transformation and microband formation offers a promising approach for designing novel high-performance alloys with exceptional strength and ductility.

引用

页数：14

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