Fracture of void-embedded high-entropy-alloy films: A comprehensive atomistic study

被引：14

作者：

Cui, Yi ^{[1
]}

Chen, Zengtao ^{[2
]}

Ju, Yang ^{[1
]}

机构：

[1] Nagoya Univ, Dept Micronano Mech Sci & Engn, Chikusa Ku, Furo Cho, Nagoya, Aichi 4648603, Japan

[2] Univ Alberta, Dept Mech Engn, Edmonton, AB T6G 2G8, Canada

来源：

MATERIALIA | 2020年 / 12卷

基金：

日本学术振兴会; 奥地利科学基金会;

关键词：

High entropy alloy; Fracture; Void growth; Polycrystalline; Void shape; MOLECULAR-DYNAMICS; DISLOCATION EMISSION; MASS-TRANSFER; GROWTH; SIMULATION; DUCTILE; TRANSFORMATION; DEFORMATION; COALESCENCE; INITIATION;

D O I：

10.1016/j.mtla.2020.100790

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Comprehensive molecular dynamics (MD) simulations are performed to study the stress response and deformation mechanism in void-embedded, single-crystal and polycrystalline, high-entropy-alloy (HEA) films under uniaxial tensile loading. Our results reveal that certain void-embedded HEA films can be, by far, superior to pure Ni in terms of tensile ductility and the resistance to crack propagation. The fracture strain of the 10%Co CoCrFeMnNi and the equiatomic CoFeMnNi, respectively, doubles or triples that of the equiatomic CoCrFeMnNi, which still doubles that of pure Ni. Regarding the deformation mechanism, high tensile ductility of HEAs can be attributed to the formation of partial dislocations, nanotwinning and the impediment of the otherwise glissile dislocations due to the lattice distortion effect. The ultimate tensile strength of HEA film shows better resistance against stress deterioration due to elliptical voids. The stress response of the void-embedded, polycrystalline Ni films obeys the reverse Hall-Petch effect, while the void-embedded, polycrystalline HEA films do not.

引用

页数：16

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