Fatigue-corrosion studies on the 2198-T851 (Al–Cu–Li) alloy containing Nb$_2$O$_5$ sputtered coating

M. O. A. Ferreira^a, K. R. dos Santos^a, R. V. Gelamo^b, N. B. Leite^b, C. A. R. Baptista^c, T. J. P. de Oliveira^d, H. C. Pinto^a, J. A. Moreto<sup>a

a</sup> São Carlos School of Engineering, University of São Paulo
^b Federal University of Triângulo Mineiro
^c Lorena School of Engineering, São Paulo State University
^d Universidade Federal de Lavras

Abstract: This research investigates the influence of Nb$_2$O$_5$ coatings, produced by using reactive sputtering technique, on the surface of middle-tension specimens M(T), regarding fatigue crack growth curves (da/dN versus DK) under exposure to a 0.6 mol NaCl saline solution. Results demonstrated the corrosion process occurred in the vicinity of the crack tip, where stresses are elevated, and significant plastic deformation prevails, notably influenced by slip bands that induce micro-cracks, exposing fresh material layers to the corrosive surroundings. The Nb$_2$O$_5$ coatings enhanced the fatigue-corrosion resistance of the 2198-T851 aluminium alloy. This study marks an initial step towards more comprehensive investigations into the impact of Nb$_2$O$_5$ coating on improving the mechanical properties of the 2198-T851 aluminium alloy.

Keywords: fatigue-corrosion synergy, reactive sputtering technique, aluminium alloy, aircraft industry.

UDC: 66.017: 66.018.2: 66.018.8

Language: English

DOI: 10.15372/PMTF202415570

 English version: Journal of Applied Mechanics and Technical Physics, 2025, 66:3, 620–632

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