Physical and Chemical Characterization of the Magnesium Surface Modified by Plasma Electrolytic Oxidation – Influence of Immersion in Simulated Body Fluid

Abstract

Pure magnesium (Mg) degrades very quickly and uncontrollably upon contact with water. It also oxidizes in the air. Plasma electrolytic oxidation (PEO) is a promising method for surface modification of metal alloys, which can contribute to controlling corrosion of Mg. Additionally, modifications with the PEO lead to the formation of mesoporous topography and changes in physical and chemical properties of Mg surfaces, e.g., their wettability, and to increase in their surface area. Our project aimed at modification of surfaces of Mg implant by the PEO method using silicate-based bath electrolyte in order to enhance resistance to corrosion, biocompatibility, and antibacterial properties of the implants. The use of silicate in the PEO bath electrolyte leads to changes in the surface morphology. The obtained surface layers acquire rich morphology with pores and craters of various sizes. This substantially increases the total surface area and change wettability. In addition, the formation of silicate oxide layers provides protection from corrosion and can lead to an improvement in the long-term stability of implants.