BaxSr(1−x)TiO3 (BST) thin films were fabricated on a Ti substrate using micro-arc oxidation (MAO) in an aqueous solution with the addition of 0.6 M Ba(OH)2, 0.4 M Sr(OH)2, and 0.05 M EDTA. The morphology, composition, and electrical properties of BST films prepared under different processing times were characterized, and MAO growth characteristics of BST films were discussed. Results indicate that dielectric and ferroelectric properties of BST films are positively correlated with surface morphology dependent on MAO spark patterns. To obtain a smooth and compact film, the large spark stage should be avoided. During MAO processes, elements from the substrate and electrolyte solution migrate in opposite directions under an electric field, resulting in Ba, Sr, Ti, and O elements exhibiting a gradient distribution between the BST film and the Ti substrate. BST film prepared using MAO is composed of two layers: an outer loose layer and an inner dense layer. In addition, because of the position of discharge breakdown continually changing, the interface between the film and the substrate is uneven. As MAO processing time increases, BST film thickness increases and ferroelectric property improves. When processing time is 15 min, the residual polarization intensity (2Pr) of the BST film is about 4.9 μC/cm2.

A CeO2/ZrO2-hydroxyapatite (HA) composite bio-ceramic coating was prepared on ZK60 magnesium (Mg) alloy by using micro-arc oxidation (MAO) and electrophoretic deposition (EPD). MAO coating was done as the basal layer was grown in alkaline electrolyte with the addition of nanoparticles (CeO2 and ZrO2) to improve the mechanical properties of coating. A HA coating as the covering layer was deposited on the surface of MAO coating for improving the biological properties of the coating. The phase compositions and morphology of coatings were monitored with X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Adhesion and wear resistance of coatings were evaluated using a scratch test and a pin-on-disc sliding wear test. The corrosion resistance of coatings was evaluated in a simulated body fluid (SBF) using electrochemical tests at 36.5 ± 0.5 °C. The experimental results showed that the CeO2/ZrO2-HA composite coating on Mg alloy effectively improved its mechanical properties and corrosion resistance. Combining MAO and EPD is a promising modification technology for degradable Mg alloys as biomaterials.