Prediction of coating durability: Early detection using electrochemical methods

Corrosion of metals has an enormous economic impact. Fortunately, the rate at which corrosion processes take place can be reduced, often to a point where, at least temporarily, corrosion is virtually non-existent. One of these, corrosion-control methods is barrier protection. The concept of barrier rotection is to separate the metal substrate rom the corrosive environment. These barriers re frequently applied in the form of coatings. Two ways to determine the suitability of a coating for a specific environment can be distinguished. The first approach involves the use of so-called accelerated tests. Accelerated testing aims to reproduce, in a much shorter time than in the field, natural degradation processes without changing the degradation mechanism. The second approach utilizes sensitive electrochemical techniques such as Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Noise Measurement (ENM) to allow early detection of relevant degradation processes under "non-accelerated" conditions. The advantages and disadvantages of both approaches will be addressed in this thesis