Publication detail

Extraordinary Response of H-Charged and H-Free Coherent Grain Boundaries in Nickel to Multiaxial Loading

ŠESTÁK, P. ČERNÝ, M. ZHANG, Z. POKLUDA, J.

Original Title

Extraordinary Response of H-Charged and H-Free Coherent Grain Boundaries in Nickel to Multiaxial Loading

Type

journal article in Web of Science

Language

English

Original Abstract

The cohesive strength of Σ3, v5, and v11 grain boundaries (GBs) in clean and hydrogen-segregated fcc nickel was systematically studied as a function of the superimposed transverse biaxial stresses using ab initio methods. The obtained results for H-free GBs revealed a quite different response of the coherent twinning boundary Σ3 to the applied transverse stresses in comparison to the other GB types. While the cohesive strength of Σ5 and Σ11 GBs increased with increasing level of tensile transverse stresses, the strength of Σ3 GB remained constant for any applied levels of transverse stresses. In the case of GBs with segregated hydrogen, the cohesive strength of Σ3 was distinctly reduced for all levels of transverse stresses, while the strength reduction of Σ5 and Σ11 GBs was significant only for a nearly isotropic (hydrostatic) triaxial loading. This extraordinary response explains a high susceptibility of Σ3 GBs to crack initiation, as recently reported in an experimental study. Moreover, a highly triaxial stress at the fronts of microcracks initiated at Σ3 boundaries caused a strength reduction of adjacent high-energy grain boundaries which thus became preferential sites for further crack propagation.

Keywords

ab initio calculations; hydrogen embrittlement; grain boundary; cohesive strength; multiaxial loading

Authors

ŠESTÁK, P.; ČERNÝ, M.; ZHANG, Z.; POKLUDA, J.

Released

8. 7. 2020

Publisher

Multidisciplinary Digital Publishing Institute

ISBN

2073-4352

Periodical

Crystals

Year of study

10

Number

7

State

Swiss Confederation

Pages from

1

Pages to

12

Pages count

12

URL

https://www.mdpi.com/2073-4352/10/7/590

Full text in the Digital Library

http://hdl.handle.net/11012/193428

BibTex

@article{BUT164471,
  author="Petr {Šesták} and Miroslav {Černý} and Zhiliang {Zhang} and Jaroslav {Pokluda}",
  title="Extraordinary Response of H-Charged and H-Free Coherent Grain Boundaries in Nickel to Multiaxial Loading",
  journal="Crystals",
  year="2020",
  volume="10",
  number="7",
  pages="1--12",
  doi="10.3390/cryst10070590",
  issn="2073-4352",
  url="https://www.mdpi.com/2073-4352/10/7/590"
}