Fabrication and Characterization of Ca–Mg–P Containing Coating on Pure Magnesium

A biodegradable Ca-P coating mainly consisting of β-tricalcium phosphate (β-TCP) was fabricated on pure magnesium via the chemical deposition in a simulated Hank's solution. The method significantly accelerated the coating formation on magnesium. Moreover, the morphology, phase/chemical composition, the coating formation mechanism as well as degradation behavior in phosphate buffered saline (PBS) solution were investigated. Scanning electron microscopy (SEM) images showed that the coating had three layers and X-ray diffraction (XRD) patterns showed that the coating mainly contained Ca3(PO4)2 and (Ca, Mg)3(PO4)2. Electrochemical test showed that the corrosion current density (Icorr) of the coated Mg was decreased by about one order of magnitude as compared to that of pure magnesium. The immersion test indicated that the coating could obviously reduce the degradation rate.