Electrophoretic deposition and corrosion performance of Zirconia-Silica composite coating applied on surface treated 316L stainless steel: Toward improvement of interface structure

Abstract

ZrO2-10 mol.% SiO2 composite coatings has been produced on 316L stainless steel, surface treated using mechanical polishing, electropolishing and anodic oxidizing procedures. For this purpose, the composite particles were prepared using sol-gel processing method, electrophoretically deposited on pre-treated substrate and then sintered at 1100 °C. The evaluations confirmed firm attachment of the coating deposited on the oxidized 316L surface, providing a dual-structure interface including dense and porous layer. Focused ion beam tomography technique was applied to study the interface. In this regard, the interface structure was reconstructed and a model was proposed based on acquired three dimensional images to describe the interlayer formation mechanism on the anodic oxidized substrate. Corrosion studies in a simulated body fluid solution indicated that the highest barrier effect was obtained on anodically oxidized surface post coating. This sample revealed the lowest corrosion current density of 0.95 nA cm−2 after 24 h immersion.