Study on the interface of PVDF coatings and HF-treated AZ31 magnesium alloy: Determination of interfacial interactions and reactions with self-healing properties

In this paper the interface of poly(vinylidene fluoride) coatings prepared by the dip coating method and HF-treated AZ31 magnesium alloy was evaluated. The best performance of this system in corrosion tests compared to ground, as-received and acetic acid cleaned substrates is related to an acid–base interaction at the interface and to interfacial reactions which resulted in a self-healing process. The protectiveness of the samples was investigated using impedance and immersion tests while the coating morphology and interface stability were investigated by scanning electron microscopy, X-ray photoelectron spectroscopy and adhesion tests.

Research highlights
► Reports a high protection system for the alloy in corrosive environment.
► Describes an interfacial process with self-healing properties.
► Reports the influence of substrate pre-treatment in the coating performance.