Publication detail

Impact of interstitial elements on the stacking fault energy of an equiatomic CoCrNi medium entropy alloy: theory and experiments

MORAVČÍK, I. ZELENÝ, M. DLOUHÝ, A. HADRABA, H. MORAVČÍKOVÁ DE ALMEIDA GOUVEA, L. PAPEŽ, P. FIKAR, O. DLOUHÝ, I. RAABE, D. LI, Z.

Original Title

Impact of interstitial elements on the stacking fault energy of an equiatomic CoCrNi medium entropy alloy: theory and experiments

Type

journal article in Web of Science

Language

English

Original Abstract

We investigated the effects of interstitial N and C on the stacking fault energy (SFE) of an equiatomic CoCrNi medium entropy alloy. Results of computer modeling were compared to tensile deformation and electron microscopy data. Both N and C in solid solution increase the SFE of the face-centered cubic (FCC) alloy matrix at room temperature, with the former having a more significant effect by 240% for 0.5 at % N. Total energy calculations based on density functional theory (DFT) as well as thermodynamic modeling of the Gibbs free energy with the CALPHAD (CALculation of PHAse Diagrams) method reveal a stabilizing effect of N and C interstitials on the FCC lattice with respect to the hexagonal close-packed (HCP) CoCrNi-X (X: N, C) lattice. Scanning transmission electron microscopy (STEM) measurements of the width of dissociated 1/2 dislocations suggest that the SFE of CoCrNi increases from 22 to 42-44 mJ center dot m(-2) after doping the alloy with 0.5 at. % interstitial N. The higher SFE reduces the nucleation rates of twins, leading to an increase in the critical stress required to trigger deformation twinning, an effect which can be used to design load-dependent strain hardening response.

Keywords

ab initio calculations; interstitials; medium entropy alloy; scanning transmission electron microscopy; stacking fault energy; strengthening

Authors

MORAVČÍK, I.; ZELENÝ, M.; DLOUHÝ, A.; HADRABA, H.; MORAVČÍKOVÁ DE ALMEIDA GOUVEA, L.; PAPEŽ, P.; FIKAR, O.; DLOUHÝ, I.; RAABE, D.; LI, Z.

Released

30. 8. 2022

Publisher

Taylor & Francis

Location

ABINGDON

ISBN

1468-6996

Periodical

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS

Year of study

23

Number

1

State

Japan

Pages from

376

Pages to

392

Pages count

17

URL

https://www.tandfonline.com/doi/full/10.1080/14686996.2022.2080512

Full text in the Digital Library

http://hdl.handle.net/11012/208474

BibTex

@article{BUT179129,
  author="Igor {Moravčík} and Martin {Zelený} and Antonín {Dlouhý} and Hynek {Hadraba} and Larissa {Moravčíková de Almeida Gouvea} and Pavel {Papež} and Ondřej {Fikar} and Ivo {Dlouhý} and Dierk {Raabe} and Zhiming {Li}",
  title="Impact of interstitial elements on the stacking fault energy of an equiatomic CoCrNi medium entropy alloy: theory and experiments",
  journal="SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS",
  year="2022",
  volume="23",
  number="1",
  pages="376--392",
  doi="10.1080/14686996.2022.2080512",
  issn="1468-6996",
  url="https://www.tandfonline.com/doi/full/10.1080/14686996.2022.2080512"
}