Preliminary study on a bioactive Sr containing Ca–P coating on pure magnesium by a two-step procedure

• The Sr–CaP coating was fabricated via the combination of chemical deposition and micro-arc oxidation.
• Ca element was incorporated in coating by pre-treatment in Ca–P containing solution.
• The corrosion resistance of Mg matrix was significantly enhanced by micro-arc oxidation.
• Sr–CaP containing coating exhibited excellent biomineralization performance.

In this study, a bioactive Sr containing Ca–P (Sr–CaP MAO) coating was obtained through the combination of preceding chemical deposition and micro-arc oxidation treatments for the purpose of modifying the surface of the magnesium to promote the bioactivity and to reduce the degradation rate. The microstructure, element and phase composition of the coating were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Electrochemical and immersion tests were conducted to evaluate the degradation behavior of the Sr–CaP MAO coating in a Hank’s solution. The results showed that Sr was successfully incorporated into the Pre-CaP coating by the two-step procedure. The in vitro degradation evaluation indicated that the Sr–CaP MAO coating could significantly reduce the corrosion rate of pure magnesium and show better biomineralization property.