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Revisiting stress-corrosion cracking and hydrogen embrittlement in 7xxx-Al alloys at the near-atomic-scale.
- Source :
- Nature Communications; 7/25/2022, Vol. 13 Issue 1, p1-9, 9p
- Publication Year :
- 2022
-
Abstract
- The high-strength 7xxx series aluminium alloys can fulfil the need for light, high strength materials necessary to reduce carbon-emissions, and are extensively used in aerospace for weight reduction purposes. However, as all major high-strength materials, these alloys can be sensitive to stress-corrosion cracking (SCC) through anodic dissolution and hydrogen embrittlement (HE). Here, we study at the near-atomic-scale the intra- and inter-granular microstructure ahead and in the wake of a propagating SCC crack. Moving away from model alloys and non-industry standard tests, we perform a double cantilever beam (DCB) crack growth test on an engineering 7xxx Al-alloy. H is found segregated to planar arrays of dislocations and to grain boundaries that we can associate to the combined effects of hydrogen-enhanced localised plasticity (HELP) and hydrogen-enhanced decohesion (HEDE) mechanisms. We report on a Mg-rich amorphous hydroxide on the corroded crack surface and evidence of Mg-related diffusional processes leading to dissolution of the strengthening η-phase precipitates ahead of the crack. High-strength Al alloys are sensitive to stress corrosion cracking and hydrogen embrittlement that limit their applications. Here the authors examine them at near-atomic scale using advanced microscopy and reveal hydrogen at dislocations and grain boundaries, and subsequent microstructural changes. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 13
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 158163232
- Full Text :
- https://doi.org/10.1038/s41467-022-31964-3