Abstract

Investigation on the corrosion-induced degradation mechanisms of Al-Cu-Li 2198 alloy is critical for the aircraft maintenance protocol. This article aims to identify the corrosion-induced degradation mechanisms of AA2198-T8; three (3) different accelerated corrosion tests with electrolytes of various aggressiveness, namely sodium chloride (NaCl), Harisson’s and exfoliation corrosion (EXCO) solution were exploited. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and immersion tests were used in this context. The EIS analyses revealed that exploitation of different electrolytes essentially affects corrosion-degradation mechanism. Intergranular corrosion attack was found to dominate in EXCO solution, while transgranular attack was evident in both, 3.5 wt. % NaCl and Harrison’s solutions. Severe localized corrosion in Harrison’s solution led to higher degradation of elongation at fracture (Af) throughout immersion duration; EXCO exposure led to higher corrosion attack rate for the short exposure times (≤ 6 hours). Correlation between the different electrolytes regarding tensile ductility decrease was attempted through a linear coefficient for the initial, small exposure times; 1-hour EXCO exposure of AA2198-T8 was found to be equivalent to 107 hours exposure to 3.5 wt. % NaCl solution, while the respective correlation with Harrison’s solution showed that 1-hour EXCO exposure is equivalent to 27 hours Harrison exposure.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.