Recubrimiento hibridos organico-inorganicos base sílice depositados por la tecnica de pulverizado(spray)

SHEILA OMAR; SERGIO PELLICE; JOSEFINA BALLARRE; CERE, SILVIA

Congreso; Congreso internacional de metalurgia y materiales Sam- Conamet/iberomat/materia 2014; 2014

Stainless steel AISI 316L is mostly used in sanitary and biomedical applications, even though it suffers pitting. Its protection is achieved by applying an organic-inorganic hybrid coating produced by sol-gel method, which modifies the metal surface acting as a barrier for ions migration. Traditionally, lab- scale sol-gel coatings are done by dip or spin coating techniques, assuring a correct surface termination and homogeneous thickness. However, these techniques have their limitations for industrial-scale due to the fact that they only allowed coating simple geometries. In this context, a technique for coatings with industrial application, low cost of implementation and less geometric limitations is spray method, fairly proved for sol-gel coatings. This paper presents the synthesis and deposition of spray sol-gel coatings, with an initial solution containing tetraethosysilane (TEOS), methytriethoxisilane (MTES) and colloidal silica nanoparticles, applied over 316L stainless steel. The deposition tuning requires adjusting all the process parameters, like: distance between the nozzle of the spray gun and the substrate, deposition rate, pressure, etc. Even the viscosity and the stability of the sol, are important factors directly related with the surface finish and final properties of the coated samples. The power covering is analyzed by optical microscopy and its roughness and thickness is studied by mechanical perfilometry. The surface integrity and homogeneity is analyzed by electrochemical tests. By this spray technique was possible to adjust the deposition parameters for obtaining homogeneous coatings applied over 316L stainless steel, with a corrosion resistance in simulated body fluid solution comparable with traditional deposition techniques.