Influence of Zirconia and Organic Additives on Mechanical and Electrochemical Properties of Silica Sol-Gel Coatings

This paper presents the result of the investigation of organically modified silica (ORMOSIL)-zirconia coatings used to enhance their protective properties, namely corrosion and scratch resistance. Two different materials, i.e., SiO₂/ZrO₂ and SiO₂/GPTMS/ZrO₂, were synthesized, measured, and analyzed to find the difference in the used organosilane precursor (dimethyldiethoxysilane and (3-glycidoxypropyl)trimethoxysilane, respectively). SiO₂/ZrO₂ coatings showed higher hardness than SiO₂/GPTMS/ZrO₂. Moreover, the value of polarization resistance (R_p) for SiO₂/GPTMS/ZrO₂ coated 316L steel relative to the uncoated one was obtained. It was nearly 84 times higher. The coating delamination was observed with load 16N. Additionally, the corrosion mitigation for 316L coated by SiO₂/GPTMS/ZrO₂ was observed even after extended exposure to corrosion agents.