Investigation of effective parameters in improving corrosion resistance of silica coated stainless steel via sol–gel method

Abstract

The sol–gel method has been used to deposit oxide thin films. In the present study, silica was coated on 316L stainless steel substrate through sol–gel method via dipping process. Silica sol was made in a mixture of methyltriethoxysilane (MTES), tetraethyl orthosilicate (TEOS), pure water, absolute ethanol as solvent, nitric acid, and hydrochloric acid as catalysts. The corrosion resistance of samples was investigated in simulated body fluid by a potentiodynamic test and uniformity of the coating was evaluated by scanning electron microscope. We have assessed the effective parameters, such as wetting agent, number of layers, catalyst and different roughness of sublayers on corrosion properties of samples. The silica coating resulted in improvement of corrosion resistance of 316L stainless steel in body environment, and can be used as a proper coating on orthopaedic implants.