A new technique for online visualization of the electrode surface under electrochemical corrosion processes

A new method for the online visualization of corrosion processes has been developed. It relates two techniques, electrochemical studies (potentiodynamic, potentiostatic, chronoamperometric etc.) and image processing. The main advantage of this method is that it is possible to relate the morphological changes of the electrode surfaces to the electrochemical signal measured without disturbing the electrochemical system. The online visualization technique is based on a horizontal electrochemical cell. The cell allows observation of the surface of the electrodes in a horizontal position by means of a triocular microscope-stereoscope assembled to an image acquisition system. The methodology was applied to the study and understanding of the surface changes of a copper and an AISI 316L electrode, respectively, when their potentiodynamic curves were taken in a lithium bromide solution. The corroded area of an AISI 316L electrode was determined by image processing in order to calculate the local current density in a potentiostatic test. The visualization method proposed can be used to gain a better understanding of electrochemical corrosion processes.