Evaluación de las propiedades anticorrosivas de sustratos metálicos recubiertos con películas delgadas de nanopartículas de óxido de zirconio

Abstract

In this work they were evaluated anticorrosive properties of thin films of zirconium oxide nanoparticles on substrates of 304 stainless steel and commercial aluminum deposited by: dip-coating and spin-coating. The synthesis of zirconium oxide nanoparticles was performed by the sol-gel method and was used zirconium oxychlorideoctahydrate as precursor and calcium acetate monohydrate as stabilizer of the zirconia structures, in a molar ratio of precursor/stabilizer of 0,84/0,16. It is considered an aging time of 24 and thermal processes of 550 and 600 ° C for 30 min respectively. The structure of the synthesized nanoparticles was determined by X-ray diffraction, the particle size by dynamic light scattering and morphology by scanning electron microscopy and transmission. In the characterization were obtained oxide zirconium nanoparticles in cubic phase, with an effective diameter particle between 7,2 and 5,2 nm at temperatures of 550 and 600 ° C respectively. The metal substrates with the better adhered coating, were evaluated their corrosion resistance in saline environment during 500 hours according to ASTM B177-11 standard. The coating allowed establishing that there is a anticorrosive protection in substrates coated when compared with uncoated substrates. In the two types of substrates, the coating deposited by dip-coating has greater corrosion resistance than deposited by spin-coating. In aluminium substrates the affect anticorrosive of coating showed better results protective that in steel substrates.