In Vitro Corrosion Behavior of Zr-Containing MAO-PLA Composite Coating on Magnesium Alloy

To improve the corrosion resistance of magnesium alloy as a medical implant, a Zr-containing micro-arc oxidation-polylactic acid (MAO-PLA) composite coating was successfully prepared. The microstructure, phase composition, and corrosion resistance of the coating were studied by scanning electron microscope, X-ray diffractometer, and electrochemical workstation. The results show that the micropores and cracks on the surface of MAO coating can be sealed by PLA, which makes the corrosion rate of the sealed sample minimum. And, in the process of immersion corrosion of simulated body fluid (SBF), calcium and phosphorus deposits are formed on the surface of the composite coating, and PLA coating plays a major role in protecting the substrate. The composite coating can be applied to degradable magnesium-based orthopedic implants.

Automated summary

A Zr-containing micro-arc oxidation-polylactic acid (MAO-PLA) composite coating was prepared to enhance the corrosion resistance of magnesium alloy as a medical implant. The study on the microstructure, phase composition, and corrosion resistance of the coating showed that PLA can seal the micropores and cracks on the surface of the MAO coating, resulting in the lowest corrosion rate for the sealed sample. In the immersion corrosion process with simulated body fluid (SBF), calcium and phosphorus deposits form on the surface of the composite coating, with PLA coating playing a vital role in substrate protection. The composite coating can be used for degradable magnesium-based orthopedic implants.