"Non-equilibrium" grain boundaries in additively manufactured CoCrFeMnNi high-entropy alloy: Enhanced diffusion and strong segregation

被引：11

作者：

Choi, Nuri ^{[1
]}

Taheriniya, Shabnam ^{[1
]}

Yang, Sangsun ^{[2
]}

Esin, Vladimir A. ^{[3
]}

Yu, Ji Hun ^{[2
]}

Lee, Jai-Sung ^{[4
]}

Wilde, Gerhard ^{[1
]}

Divinski, Sergiy V. ^{[1
]}

机构：

[1] Univ Munster, Inst Mat Phys, D-48149 Munster, Germany

[2] Korea Inst Mat Sci, Powder Mat Div, Chang Won 51508, South Korea

[3] PSL Univ, Ctr Materiaux CNRS, UMR 7633, Mines Paris, F-91003 Evry, France

[4] Hanyang Univ, Dept Mat Sci & Chem Engn, Ansan 15588, South Korea

来源：

JOURNAL OF APPLIED PHYSICS | 2022年 / 132卷 / 24期

关键词：

OF-THE-ART; MECHANICAL-PROPERTIES; TRACER DIFFUSION; RESIDUAL-STRESS; SELF-DIFFUSION; MICROSTRUCTURE; STRENGTH; SOLIDIFICATION; DISLOCATIONS; STABILITY;

D O I：

10.1063/5.0133144

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Grain boundary diffusion in an additively manufactured equiatomic CoCrFeMnNi high-entropy alloy is systematically investigated at 500 K under the so-called C-type kinetic conditions when bulk diffusion is completely frozen. In the as-manufactured state, general (random) grain boundaries are found to be characterized by orders-of-magnitude enhanced diffusivities and a non-equilibrium segregation of (dominantly) Mn atoms. These features are explained in terms of a non-equilibrium state of grain boundaries after rapid solidification. The grain boundary diffusion rates are found to be almost independent on the scanning/building strategy used for the specimen's manufacturing, despite pronounced microstructure differences. Grain boundary migration during diffusion annealing turned out to preserve the non-equilibrium state of the interfaces due to continuous consumption of the processing-induced defects by moving boundaries. Whereas the kinetic "non-equilibrium " state of the interfaces relaxes after annealing at 773 K, the non-equilibrium segregation is retained, being further accompanied by a nano-scale phase decomposition at the grain boundaries. The generality of the findings for additively manufactured materials is discussed. Published under an exclusive license by AIP Publishing.

引用

页数：14

共 80 条

[21] EFFECT OF GRAIN-BOUNDARY MIGRATION ON APPARENT BOUNDARY DIFFUSION-COEFFICIENTS [J].