Detection of corrosion by digital speckle pattern interferometry

It has been recently shown that application of Michelson interferometry, is suitable for monitoring of oxide layers growing in metallic structures during preliminary states of oxidation processes in aqueous solutions, without any physical contact with the sample. The qualitative and quantitative interpretation of the observed interferograms allows evaluation of important physical parameters related to specific corrosion processes [1]. Although the using of aluminum samples with surfaces polished to certain optical quality is a necessary requirement to obtain well-built interferograms, it complicates further applications for diffused surfaces typical of industrial conditions. In this work we present preliminary qualitative results obtained by using a simple experimental setup based on Digital Speckle Pattern Interferometry (DSPI) [2], as a proposal to solve this difficulty and on the other hand, to use the benefits of certain powerful tools like low-coherence optical techniques for further applications on monitoring of corrosion through turbid media.