resumo
Plasma electrolytic oxidation (PEO) with in situ anatase particle addition is applied to functionalize the surface of AA2024 alloy. A base potassium titanium oxide oxalate dihydrate aqueous electrolyte is used with up to 30 g L-1 anatase particle addition. The coatings' morphology and phase composition as a function of the anatase concentration in the electrolyte are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES). Photocatalytic activity, stability in chloride solution, and tribological properties are also determined. The main coating forming phases are anatase and rutile on top of a mixed interface region consisting of TiAl2O5 as reaction product between the TiO2 and an Al2O3 barrier layer on top of the Al substrate. The mixed layer is extending with increasing amount of particles added, due to intensified discharges. In addition, anatase-to-rutile phase ratio increases due to the additional anatase particles in the electrolyte. Thus, the photocatalytic activity is improving with the particle addition. The coatings' mechanical resistance is dropping first before increasing again with more particles added. Chemical and restored mechanical stability seems to be related to the extended mixed interface formation, which strengthens the bond to the substrate when more particles are added.
categoria
Materials Science, Multidisciplinary
autores
Ignjatovic, S; Blawert, C; Serdechnova, M; Karpushenkov, S; Damjanovic, M; Karlova, P; Dovzhenko, G; Wieland, DCF; Zeller-Plumhoff, B; Starykevich, M; Stojanovic, S; Damjanovic-Vasilic, L; Zheludkevich, ML
nossos autores
Maksim Starykevich
Investigador Júnior
Mikhail Zheludkevich
Investigador Principal Convidadoagradecimentos
This work was partially supported by Research Executive Agency (European Commission) in frame of Horizon2020-MSCA/RISE-2018 FUNCOAT project (grant agreement no. 823942, Development and design of novel multiFUNctional PEO COATings). The authors thank Anton Davydok for the experimental support within DESY beamline experiments. They also thank PETRA III (Hamburg, Germany) for granting the P03 proposal I-20191340 for localized phase composition analysis.; Open access funding enabled and organized by Projekt DEAL.