Fast visualization of corrosion processes using digital speckle photography

This work shows the feasibility of using non-intrusive optical techniques to determine surface changes associated with corrosion processes even when they are very small and to obtain complementary information to the conventional electrochemical measurements. These techniques have been applied to the study of iron samples in H2SO4 corrosive solutions with different concentrations. Corrosion rate values have been estimated from the polarisation and Tafel curves obtained by linear sweep voltammetry. These measurements have been correlated with the surface changes determined from Digital Speckle Photography. This technique also provides a local 2D information about the evolution of the corrosion process at each surface position.