A novel Mg(OH)2/MgFx(OH)1−x composite coating on biodegradable magnesium alloy for coronary stent application

To enhance the corrosion resistance of bioabsorbable magnesium alloys, a Mg(OH) 2 /MgF x (OH) 1-x inorganic coating was prepared on a AZ31B magnesium alloy by a simple two-step immersion approach. The surface analysis, processing optimization, adhesion properties, in vitro corrosion behavior and biocompatibility were investigated. The composite coating significantly improved the adhesion of poly(trimethylene carbonate) coating on the surface (level 1). The corrosion resistance of the optimized sample was significantly improved ( I corr =7.1 × 10 -8 A·cm –2 ) due to the blocking of defects by the Mg(OH) 2 nanosheet. In addition, the optimized sample exhibited better in vitro cytocompatibility and hemocompatibility. • NaOH treatment blocked some defects of the hydrofluoric acid coating. • NaOH treatment improved the anti-corrosion performance of the coating. • NaOH treatment can improve the adhesive ability of polymers on its surface. • The modification has the advantages of simplicity, low-cost and nontoxicity