Optical sensors for corrosion detection in airframes

The use of sensors to detect aluminium corrosion in airframe structures could allow reducing significantly the maintenance costs of fleets. An appropriate sensor may detect corrosion at an early stage, when the removal of the corroded material from the original structure does not involve a structural repair. Moreover, by guaranteeing that corrosion is locally detected by an efficient sensor, the need for inspections in some areas could be eliminated or, at least, inspection intervals could be increased, with significant reduction of costs but still maintaining a conservative approach for aircraft safety. In the present work an optical sensor is presented, that can be used to detect corrosion products inside critical aircraft joints which are known to be very susceptible to corrosion. This sensor is based on the remote detection of aluminium ions produced in the corrosion process. The proposed method for the preparation of these sensors and the results obtained will be discussed. (C) 2013 Elsevier B.V. All rights reserved.