It is reported in literature that organic coatings obtained with silane solution pre-treatements act as a physical barrier which delays the access of aggressive species to the metallic substrate and thus provide corrosion protection. This effect can be enhanced adding the silane solution with nanoparticles of several oxides, in particular, it was proved that CeO2-ZrO2 nanoparticles improved the barrier properties of the modified silane coatings. The protective effect of pre-treatments with 3-Mercapto-Propyl-Trimethoxy-Silane modified with nanoparticle oxides applied on AZ31 Magnesium alloy was studied by electrochemical techniques (Potentiodynamic Polarization Curve recording, Impedance Spectroscopy) in a solution of 0.1 M NaCl, while the silane film features were analyzed by FTIR Spectroscopy. The protective coatings were obtained dipping, at room temperature, AZ31 specimens for 30 s in a hydro-alcoholic solution of 3-Mercapto-Propyl-Trimethoxy-Silane added with an aqueous nanoparticle suspension of Cerium, Cerium-Zirconium, Zirconium-Titanium oxides at 250 ppm concentration (at pH 4). The specimens were cured for 1 h at 100 °C. The nanoparticle concentration effect was studied by increasing the CeO2-ZrO2 concentration to 500 ppm
Corrosion behaviour of AZ31 Magnesium alloy pre-treated with silane solutions modified with nano-particle oxides.
ZANOTTO, Federica;GRASSI, Vincenzo;FRIGNANI, Alessandro;MONTICELLI, Cecilia;BALBO, Andrea;ZUCCHI, Fabrizio
2009
Abstract
It is reported in literature that organic coatings obtained with silane solution pre-treatements act as a physical barrier which delays the access of aggressive species to the metallic substrate and thus provide corrosion protection. This effect can be enhanced adding the silane solution with nanoparticles of several oxides, in particular, it was proved that CeO2-ZrO2 nanoparticles improved the barrier properties of the modified silane coatings. The protective effect of pre-treatments with 3-Mercapto-Propyl-Trimethoxy-Silane modified with nanoparticle oxides applied on AZ31 Magnesium alloy was studied by electrochemical techniques (Potentiodynamic Polarization Curve recording, Impedance Spectroscopy) in a solution of 0.1 M NaCl, while the silane film features were analyzed by FTIR Spectroscopy. The protective coatings were obtained dipping, at room temperature, AZ31 specimens for 30 s in a hydro-alcoholic solution of 3-Mercapto-Propyl-Trimethoxy-Silane added with an aqueous nanoparticle suspension of Cerium, Cerium-Zirconium, Zirconium-Titanium oxides at 250 ppm concentration (at pH 4). The specimens were cured for 1 h at 100 °C. The nanoparticle concentration effect was studied by increasing the CeO2-ZrO2 concentration to 500 ppmI documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
