In-situ investigation of crevice corrosion by electrochemical noise analysis

Aluminum and Al-alloys are one of the most important materials in the aircraft industry. The corrosion behaviors are well known for such materials and usually sufficient for applications. A special corrosion phenomen is the crevice corrosion because it is foreseeable and difficult to measure. Aircrafts possess a lot of crevices, especially on riveted connections. The authors used a special corrosion cell for in-situ investigation of crevice corrosion which is described in detail in /1,2/. The influence of small crevices in corrosion behaviors was shown by the evidence of conventionally electrochemical methods /1-3/. The electrochemical noise analysis is an interesting method to investigate dynamic processes in the initial state of crevice corrosion /4/. J. C. URUCHURTU et al. described in /5,6/ initial processes of pitting corrosion of aluminum in the presence or absence of chloride ions. In this work the authors present results of noise analysis carried out inside small crevices which have a width of between 0.05 and 0.2 mm. Therefore we can test the material under crevice conditions without material damage. We observed the influence of crevices on the surface activation process in sulfate and chloride solutions.