Abstract

Hydrogen embrittlement (HE) causes sudden, costly failures of metal components across a wide range of industries. Yet, despite over a century of research, the physical mechanisms of HE are too poorly understood to predict HE-induced failures with confidence. We use non-destructive, synchrotron-based techniques to investigate the relationship between the crystallographic character of grain boundaries and their susceptibility to hydrogen-assisted fracture in a nickel superalloy. Our data lead us to identify a class of grain boundaries with striking resistance to hydrogen-assisted crack propagation: boundaries with low-index planes (BLIPs). BLIPs are boundaries where at least one of the neighboring grains has a low Miller index facet—{001}, {011}, or {111}—along the grain boundary plane. These boundaries deflect propagating cracks, toughening the material and improving its HE resistance. Our finding paves the way to improved predictions of HE based on the density and distribution of BLIPs in metal microstructures.

Details

Title
Crystallographic character of grain boundaries resistant to hydrogen-assisted fracture in Ni-base alloy 725
Author
Hanson, John P 1   VIAFID ORCID Logo  ; Bagri, Akbar 2 ; Lind, Jonathan 3 ; Kenesei, Peter 4 ; Suter, Robert M 5   VIAFID ORCID Logo  ; Gradečak, Silvija 6 ; Demkowicz, Michael J 7   VIAFID ORCID Logo 

1  Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA 
2  Department of Civil Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA 
3  Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA; Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA 
4  Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA 
5  Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA 
6  Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA 
7  Materials Science and Engineering, Texas A&M University, College Station, TX, USA 
Pages
1-11
Publication year
2018
Publication date
Aug 2018
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-018-05549-y
ProQuest document ID
2092507776
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.