Preparation and Corrosion Properties of Dicalcium Phosphate Dihydrate Coating Electrodeposited on AZ31 Mg Alloys

In order to solve the problem caused by rapid corrosion of magnesium (Mg) and its alloys in clinical application, dicalcium phosphate dihydrate (DCPD) coatings with different current densities (0.1 mA cm−2, 0.4 mA cm−2, 1.0 mA cm−2) and deposition time (10 min, 30 min, 60 min) were prepared by galvanostatic deposition method with the Mg alloys as the cathode. The effects of current density and deposition time on the structure and composition of coatings were analyzed by scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction. Electrochemical corrosion results showed that the polarization resistance of the 0.4 mA cm−2−30 min sample was 68 times that of Mg alloy. And 7 d of long-term corrosion also confirmed its predominant corrosion resistance (hydrogen evolution was only 1/7 of that of Mg alloy), and better biomineralization ability. This was undoubtedly helpful to improve the mechanical integrity and biocompatibility of Mg alloy, thus enhancing the possibility of their clinical application.