Corrosion resistance studies of copper and magnesium-doped fluorohydroxyapatite coatings on titanium biomaterial

Abstract

This study discusses the contribution of Cu²⁺ and Mg²⁺, two biologically important ions substituted into the structure of fluorohydroxyapatite. FHA, a partial substitution of fluorine ion in HA has received a great attention because it improves the corrosion resistance of orthopedic implants. Copper, Magnesium and copper-Magnesium doped fluorohydroxyapatite (FHA) coatings were electrochemical deposited on titanium (Ti) using a cyclic voltammetry technique. The coatings properties were identified by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The corrosion behavior of coated and uncoated samples, immersed for 7 days in aerated simulated body fluid (SBF) in a presence of 0.2 g/l human serum albumin (HAS) was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The synergetic effect of albumin and doped elements on the degradation of Ti was studied. As a result of these investigations, it is revealed that: fluoride, copper and magnesium were successfully incorporated into apatite lattice structure. The additions of ions in FHA crystal matrix reduced the crystallite size, increased the crystallinity and changed the structure of F-hydroxyapatite. All the electrochemical techniques employed demonstrated that the coatings that were produced offered superior protection against corrosion for titanium when exposed to artificial body fluids. The nano-Mg-FHA coating improves effective protection to Ti and presents the highest corrosion resistance. The outcomes of this investigation were also compared with already published works to validate the research results.

Keywords:

• Titanium
• corrosion
• fluoro hydroxyapatite
• coatings
• biomedical implants

Disclosure statement

The authors declare that they have no conflict of interest.