Modification of hydroxyapatite-based coating in the presence of polyvinylalcohol (PVA) for implant application: Corrosion, structure and surface study

Highlights: • Bio-compatible HA-based thin films modified with PVA applied on AZ31 Mg alloy improved its corrosion resistance. • Concentration of PVA affect the microstructure, anti-corrosion resistance of HA coatings in NaCl and SBF solutions. • Direct addition of PVA to HA results in better corrosion performance in compare with post-treatment process. Eco-friendly hydroxyapatite-based coating modified by polyvinylalcohol (PVA) was used as a protective layer for Mg AZ31 substrates. Anti-corrosion performance of coatings was examined in both sodium chloride 3.5 wt% and simulated body fluid (SBF) solutions. The best performance against corrosion was achieved in the one-step process with a PVA concentration of 0.05 wt% and an immersion time of 60 min. The FE-SEM images also have shown that the irregularity of morphology was evident for the samples treated longer than 60 min. The results showed that the HA+PVA 0.05 wt% coated AZ31 Mg alloy causes less corrosion of Mg in the SBF solution.