Título del trabajo: ?Corrosion Protection of AZ91D Mg Alloy by a Cerium Coating Obtained in the Presence of Citric Acid?.

ANA PAULA LOPERENA; IVANA LETICIA LEHR; SILVANA BEATRIZ SAIDMAN

Buenos Aires

Congreso; Latin Corr 2018; 2018

Magnesium and its alloys are biocompatible and biodegradable materials and then they are an ideal alternative for implants of metallic biomaterials. However, this application is limited due to the high corrosion velocity of magnesium in the physiological environment [1].Cerium coatings have been studied as an environmental friendly option to enhance the corrosion resistance of magnesium alloys [2, 3]. In this work the formation of a coating from a solution containing cerium nitrate (Ce(NO3)3), citric acid (H3Cit) and hydrogen peroxide (H2O2) was studied in order to improve the anticorrosive performance of AZ91D magnesium alloy in simulated physiological solution (Ringer solution). The characterisation of the films was performed by electrochemical and surface analysis techniques such as SEM, EDS, X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The degree of corrosion protection achieved was evaluated in Ringer solution by monitoring the open circuit potential, polarisation techniques and electrochemical impedance spectroscopy (EIS).The best corrosion resistance was obtained for the coating generated in a solution containing 50 mM Ce(NO3)3, 50 mM H3Cit and 6 mM H2O2 at 50 ºC by applying ? 0.75 V during 30 minutes. The improvement in the corrosion performance is associated with the corrosion inhibition properties of H3Cit.