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Titanium dioxide (TiO2) thin films are widely used in transparent optoelectronic devices due to their excellent properties, as well as in photocatalysis, cosmetics, and many other biomedical applications. In this work, TiO2 thin films were deposited onto AISI 304 and AISI 316L stainless steel substrates by atomic layer deposition, followed by comparative evaluation of the mixture of anatase and rutile phase by X-ray diffraction, Raman maps, morphology by SEM-FEG-AFM, and adhesion of the films on the two substrates, aiming to evaluate the scratch resistance. Raman spectroscopy mapping and X-ray diffraction with Rietveld refinement showed that the films were composed of anatase and rutile phases, in different percentages. Scratch testing using a diamond tip on the TiO2 film was employed to evaluate the film adherence and to determine the friction coefficient, with the results showing satisfactory adherence of the films on both substrates.

In aircraft and storage fuel tanks, many environmental corrosion factors can be present, which can cause breakdown to the passive film of aluminum causing severe localized corrosion. Aiming to a solution to this problem, diamond-like carbon (DLC) films were deposited on substrates Al 2024-T3, Al 5052-H32, and Al 6061-T6. The substrates with and without DLC films were submitted to a corrosive immersion test with aviation fuel Jet-A1 and AVGAS 100LL. The surface morphology from aluminum substrates with and without DLC films was analyzed before and after 7 and 30 days of corrosive immersion tests by SEM. The adhesion of the DLC films was evaluated according to the ASTM-C1624 scratching test standard, and the optical profilometry was used to measure the thickness and roughness. Silver nanoparticles were also added in DLC films samples due to its antibacterial properties to check the stability and resistance against corrosive fuel medium. The results indicated an improvement of corrosion resistance just with DLC films. The silver nanoparticles did not present any advantages in this corrosion protection, and the aluminum alloys suffered more corrosion than when protected by DLC films. K E Y W O R D SAl 2024-T3, Al 5052-H32, Al 6061-T6.