Electrochemical and Morphological Characterization of Silver Doped Bioceramic Layer on Metallic Implant Materials for Orthopaedic Application

Abstract

This study presents the production of silver doped bioactive calcium-phosphate (CaP) coatings on commonly used orthopaedic implant materials (Ti6Al4V). The deposition process was performed by pulse current technique from electrolyte containing the appropriate amount of Ca(NO3)2 and NH4H2PO4 components at 70 °C. In order to modify the CaP layer, Ag+ ions were added to the base electrolyte. The electrochemical behaviour of the coatings was investigated by potentiodynamic polarization method in conventional Ringer’s solution in a three-electrode open cell. The corrosion properties of samples prepared with different parameters were compared. During immersion, the coating comes into contact with the electrolyte and corrosion occurs. Due to the potential difference between layer and the metallic substrate, discrete anodic and cathodic areas can be formed, which result in the release of silver and calcium ions. For antimicrobial applications of the modified CaP coated implant alloys, it is important to maintain a continuous release of silver ions, while the bioactive CaP layer enhance the biocompatibility properties of the layer by fostering the bone cell growth. The morphology and grain size of coatings as deposited have been investigated and confirmed by different methods such as Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) analysis.