This study considers the regularities in the formation of amorphous–crystalline coatings with zinc oxide and wollastonite particles via micro-arc oxidation (MAO) on metal substrates made from a Mg-0.8 wt.% Ca alloy. The combination of components with increased antibacterial and osteogenic properties made it possible to obtain a unique bioactive and corrosion-resistant coating that slowed down the bioresorption of a magnesium implant and stimulated the processes of osteointegration. The coating was examined using various methods, including scanning and transmission electron microscopy, X-ray crystallography, scratch testing, energy-dispersive X-ray spectroscopy, and potentiodynamic polarization testing. As a result of plasma-chemical interactions between electrolyte components and the magnesium substrate, a porous amorphous–crystalline coating comprising wollastonite (CaSiO₃), zinc oxide (ZnO), forsterite (Mg₂SiO₄), and periclase (MgO) was formed at varying voltages (350–500 V) during the MAO process. The protective properties of the coating were exceptional, as evidenced by the mass loss values of the coated samples (1.4–2.3%) in 0.9% NaCl solution, which were significantly lower than the mass loss of the uncoated alloy (8.9%). The coating synthesized at a voltage of 500 V was characterized by a maximum zinc content of 8 at.%, which was responsible for the highest antibacterial activity against Staphylococcus aureus (99.1%).

This study examines the effects of electrolyte composition, specifically the incorporation of dispersed particles, on the properties and formation kinetics of micro-arc oxidation (MAO) coatings on a bioinert titanium alloy. Coatings with particles of β-tricalcium phosphate (CP), wollastonite (CS), and combined coatings containing both types of particles (SP) were obtained. The MAO process was carried out using a Micro-Arc 3.0 unit in pulsed potentiostatic anode mode, with the process voltage ranging from 350 to 500 volts. The surface morphology and internal structure of the coatings were examined using scanning electron microscopy. The elemental composition of the coatings was determined by the EDX method, while the phase composition and fine structure of the coatings were investigated by XRD and TEM methods, respectively. The adhesion properties of the coatings were determined by means of scratch testing. When the MAO process voltage was increased to 500 V, the thickness of CP, CS, and SP coatings increased to 80, 50, and 50 μm, respectively. Notably, SP coatings demonstrated the highest adhesion strength (critical load L_c = 22 N), indicating their potential for use in load-bearing medical implants, where preventing delamination under mechanical stress is critical.