Porous Biocoatings Based on Diatomite with Incorporated ZrO₂ Particles for Biodegradable Magnesium Implants

In the present work, the surface of a biodegradable Mg alloy was modified to create porous diatomite biocoatings using the method of micro-arc oxidation. The coatings were applied at process voltages in the range of 350-500 V. We have studied the influence of the addition of ZrO₂ microparticles on the structure and properties of diatomite-based protective coatings for Mg implants. The structure and properties of the resulting coatings were examined using a number of research methods. It was found that the coatings have a porous structure and contain ZrO₂ particles. The coatings were mostly characterized by pores less than 1 μm in size. However, as the voltage of the MAO process increases, the number of larger pores (5-10 μm in size) also increases. However, the porosity of the coatings varied insignificantly and amounted to 5 ± 1%. It has been revealed that the incorporation of ZrO₂ particles substantially affects the properties of diatomite-based coatings. The adhesive strength of the coatings has increased by approximately 30%, and the corrosion resistance has increased by two orders of magnitude compared to the coatings without zirconia particles.