Selected properties of ZnO coating on Mg-based alloy for biomedical application

Abstract

Magnesium and its alloys are interesting materials for biodegradable implant applications. Magnesium alloys have very good strength properties, they are lightweight, but their main disadvantage is a low corrosion resistance in the physiological environment. Various modifications of a Mg alloys surface by deposition of di erent coatings are used to prevent untimely dissolution. The article presents the investigation results of a thin ZnO coating deposited on a MgCa2Zn1Gd3 alloy by means of the magnetron sputtering method. The studies include: scanning electron microscope observation of the ZnO surface, X-ray phase analysis, surface roughness measurement in atomic force microscopy, the microhardness test and potentiodynamic corrosion resistance test in the Ringer solution at 37?C. It was found that the ZnO coating is compact and continuous. It increases the hardness of the MgCa2Zn1Gd3 alloy and also improves its corrosion resistance. The corrosion potential is shifted slightly towards the positive values from –1.52 V to –1.50 V for the alloy with the ZnO coating.