Detecting Corrosion from Electrochemical Noise
Materials engineers can now 'listen in' on the 'noises' made by localised corrosion of, for example, metals rusting in water thanks to a new technique for monitoring to the electrochemical current and potential fluctuations of corrosion in materials. The 'noise' of corrosion in materials is helping researchers gain a greater understanding of how the process works and how they can best manage the problems caused by corrosion
The novel technique, developed by researchers at the Corrosion and Protection Centre at the University of Manchester Institute of Science and Technology (UMIST), uses three electrodes to pick up the background noise caused by fluctuations in the electrochemical reactions that take place in the corrosion process.
Bob Cottis, part of the research team at the Centre says, "Until relatively recently these fluctuations were simply regarded as a nuisance that interfered in the real task of measuring average behaviour. There is little doubt that these electrochemical noise signals contain information about the corrosion process."
The technique could be used to identify between various types of localised corrosion, such as pitting, crevice corrosion and stress corrosion cracking. No automated technique yet exists for commercial on-line monitoring.
This item is due to appear as "Listening to corrosion" by Bob Cottis, in the August issue of Materials World, Volume 7, Issue 8, p.482.
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