Unravelling corrosion degradation of aged aircraft components protected by chromate-based coatings

Journal article (2024)

Authors

A.J. Cornet Team Arjan Mol - Mechanical, Maritime and Materials Engineering , Royal Netherlands Air Force
A.M. Homborg Netherlands Defence Academy, Team Arjan Mol - Mechanical, Maritime and Materials Engineering
P. Ravi Anusuyadevi Team Arjan Mol - Mechanical, Maritime and Materials Engineering
L. 't Hoen-Velterop National Aerospace Laboratory, Marknesse
J.M.C. Mol Team Arjan Mol - Mechanical, Maritime and Materials Engineering
Research Group
Team Arjan Mol (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2024 A.J. Cornet, A.M. Homborg, P. Ravi Anusuyadevi, L. 't Hoen-Velterop, J.M.C. Mol
DOI: https://doi.org/10.1016/j.engfailanal.2024.108070
More Info
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Published Date

2024

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Materials Science and Engineering

Research Group

Team Arjan Mol

Abstract

Despite extensive research, eliminating hexavalent chromium-based inhibitors from aerospace coatings remains challenging due to a lack of understanding of coating degradation during aircraft service. This study addresses the issue by investigating the protective mechanisms and aging processes of chromate-containing coatings on aircraft components after service for over 35 years. Four aircraft parts underwent visual inspection, disassembly, and analysis using scanning electron microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). While most coating areas remained intact after extended use, three distinct degradation modes were identified: tip erosion, corrosion around rivets, and corrosion around fasteners at the leading edge. These findings reveal the complexity of corrosion protection, emphasizing that hexavalent chromium-containing coatings may not offer comprehensive protection at local design heterogeneities. The study also highlights the need to revisit traditional laboratory analysis protocols based on accelerated corrosion testing of oversimplified sample configurations, given the revealed end-of-service failure mechanisms.