Whole pH range anti-corrosion property of aluminium alloy coated with MFI zeolite film

Abstract

Strong protection capability of zeolite coating for AA6061 substrate from corrosion in NaCl, H2SO4 and NaOH solution has been demonstrated with reduction of corrosion current by five orders of magnitude. Film resistance was identified as the governing parameter in the formation of a barrier shielding the penetration of aggressive species. For the MFI zeolite film growth on the surface of the AA6061 substrate, while the in situ crystallisation (InC) protocol generated loosely packed film made of large zeolite crystal, the dry-gel conversion (DGC) protocol prepared dense film comprising of nanoparticles. Superior protection ability of DGC-grown film is attributed to the increased film resistance associated with a dense and impermeable zeolite layer. As such, the DGC-grown film requiring thinner film thickness around 5 μm showed better anti-corrosion function than the InC-grown film. This paper is part of a supplementary issue from the 17th Asia-Pacific Corrosion Control Conference (APCCC-17).