Fabrication of corrosion-resistant chitosan–gelatin–bioactive glass-ZnO/CeO2 hybrid coating on magnesium ZK60 alloy by AC-EPD

Abstract

A hybrid coating was fabricated on ZK60 magnesium (Mg) alloy using alternating current electrophoretic deposition (AC-EPD). The hybrid coating comprised chitosan, gelatin (Type-B), bioactive glasses (BG(a,b)) and nanoparticles of ZnO/CeO2. Fourier-transform infrared (FTIR) spectra confirmed the presence of the above-mentioned materials on coated samples. Scanning electron microscopy (SEM) images showed that coating morphology was homogeneous and covered the maximum surface area. Potentiodynamic polarization measurements (PDP) of coated samples were investigated in Ringer’s solution at 25°C. PDP results showed that lowest corrosion current density values of 1.39 and 1.84 µA cm−2 were observed for suspensions CS0.8–G0.8–BG(b)1.0–ZnO0.6 and CS0.8–G0.8–G(a)1–CeO2(0.6), respectively. SEM analysis and PDP results confirmed that best AC-EPD parameters for ZK60 are (Voltage = 35 V, Frequency = 300 Hz, DC off-set = 2 V, Time = 480 s, Distance = 10 mm). DC off-set with the same direction to high amplitude peak was a promising addition in AC-EPD parameters.