Structural and Morphological Features of the Ultrasound-Assisted Micro-arc Oxidation Coatings

Studying the influence of ultrasound (US) treatment during the micro-arc oxidation (MAO) process on the structural and morphological features of the calcium phosphate coatings deposited on titanium surface has been performed. The coatings with hierarchical gradient layer-by-layer structure were formed during the US-assisted MAO process. Transmission of the US waves through the electrolyte during the MAO process led to the increase of the coating thickness, to the formation of the local macropores in the boundary layer, and to the destruction of the structural elements and filling of pore spaces by fragments on the coating surface.