Hydroxyapatite powders were prepared by a chemical precipitation method and electrophoretically deposited on Ti6Al4V surgical alloy substrates. The powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), particle size distribution and zeta potential measurements. Prior to electrophoretic deposition, anodic films were obtained on Ti6Al4V and studied by the Auger method. It was established that experimental conditions of powder preparation, electric field and stirring have a significant influence on suspension stability and deposit morphology. The deposition yield was studied at various deposition durations and applied voltages. Sintered coatings were studied by SEM and XRD.

ZrO2 coatings were deposited on graphite and titanium from an aqueous solution based on a water‐soluble precursor. A two‐step mechanism is suggested for the ZrO2 formation: generation of hydroxyl ions (OH−) at the cathodic substrate by reduction of NO3− and dissolved O2 , and then reaction of the hydroxyl ions with zirconyl ions present in the solution to form the hydroxide normalZrfalse(OH)4 , which in turn decomposes on drying to yield zirconia false(ZrO2false) . Faradaic efficiencies of 20–50% were found, attributable to reduction reactions that do not produce hydroxyl ions, as well as to formation of the hydroxide at sites removed from the cathodic substrate due to diffusion of the hydroxyl ions. The effects of current density, time, and hydrodynamic conditions on coating weight, cell voltage, temperature, and pH of the solution were studied.

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