DI-UMONS : Dépôt institutionnel de l’université de Mons

Recherche transversale
(titres de publication, de périodique et noms de colloque inclus)
2017-09-06 - Colloque/Présentation - poster - Anglais - 1 page(s)

Thai Thu Thuy, Druart Marie-Eve , Trinh Anh Truc, Olivier Marie-Georges , "Compatibility between mesoporous sol-gel thin films and epoxy primers for corrosion protection of 2024 aluminum alloys substrates" in SOLGEL2017, Liège, Belgium, 2017

  • Codes CREF : Enseignement des sciences de l'ingénieur (DI0132), Corrosion des matériaux (DI2114)
  • Unités de recherche UMONS : Science des Matériaux (F502)
  • Instituts UMONS : Institut de Recherche en Science et Ingénierie des Matériaux (Matériaux)
  • Centres UMONS : Ingénierie des matériaux (CRIM)

Abstract(s) :

(Anglais) The sol-gel chemistry is based on the hydrolysis and condensation reactions of precursors, offering a large range of materials used in many applications. In recent years, sol-gel coatings have become one of the most promising methods in corrosion protection of materials. 2024 aluminum alloy (AA2024) is widely used in aerospace industry due to its low weight and its passive behavior. However, due to the presence of alloying elements as Cu, Mn, Fe, etc…, this alloy is sensitive to localized corrosion. Chromated-based conversion treatments and epoxy primers are known to be very efficient for corrosion protection of AA2024. Unfortunately, due to the effect on human health and environment, hexavalent chromium (VI) will be forbidden in 2017. As a consequence, the sol-gel coating is considered as aa friendly-environmental way to avoid the use of chromate in conversion coatings. In this work, silica-based sol-gel films were applied on AA2024 as first layer of surface treatment before the application of an epoxy primer as top layer. Non porous and mesoporous sol-gel films were synthetized. The main objective is to highlight the role of pretreatment porosity and organic precursors on corrosion resistance and compatibility with the primer. A higher surface specific area of mesoporous films and the good choice of organic precursors could promote adhesion between the metal and the organic primer. Mesoporous sol-gel films were synthetized via Evaporation Induced Self-Assembly (EISA) method by adding a templating agent in the solution containing tetraethylorthosilicate (TEOS) as precursor and absolute ethanol as solvent. Two different templating agents were used: Pluronic P123 and F108 to synthetize sol-gel films with different pore sizes. 3-glycidoxypropyltrimethoxysilane (GPTMS) was added in the mixture to investigate the role of organic precursor on the adhesion performance. The characterization of the film porosity (pore volume, specific surface area, and pore diameter) was performed by adsorption porosimetry using a quartz crystal microbalance. The corrosion protection of AA2024 samples pre-treated and painted with epoxy coating was studied using electrochemical impedance spectroscopy. The compatibility between sol-gel thin films and epoxy primer was studied by using adhesion test and salt spray test.