Surface characterization and corrosion behavior of chitosan-HA coatings on Ti6Al4V using electrophoretic deposition

Abstract

This study investigates the development and characterization of hydroxyapatite (HA) and chitosan (CS) nanocomposite coatings on Ti6Al4V alloy using the electrophoretic deposition (EPD) technique. Titanium alloys, known for their superior mechanical properties and corrosion resistance, often lack bioactivity, which can be enhanced through HA/CS coatings. HA, with a composition similar to bone mineral, provides bioactivity, while CS contributes antibacterial properties and biodegradability. The study explores the influence of varying deposition voltages (10, 20, 30, and 40 V) on the morphology, corrosion resistance, and adhesion properties of the coatings. The coatings were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, and atomic force microscopy (AFM). Results showed that increased deposition voltage led to higher porosity and thickness in the coatings, with a uniform microstructure achieved at 20 V. Electrochemical impedance spectroscopy (EIS) revealed that coatings deposited at 20 V exhibited the highest corrosion resistance due to an optimal balance of porosity and barrier properties. The study highlights the potential of EPD as a reliable method for fabricating HA/CS composite coatings on titanium alloys. The findings indicate that an optimal voltage of 20 V enhances coating uniformity and corrosion resistance making the coatings suitable for biomedical implants.