mm-wave resonant methods for the detection of corrosion

We propose a study of the ch^Lcal kinetics and ri^chanismsof corrosion relevant to aircraft through the use of ^Lllimeter-wave resonant tools. This technique, based on the use of quasi-optical resonators, is non-invasive in rature and is highly sensitive to and can accurately characterize srnall changes in surface conductivity. As such, it rnay be able to provide a means of early detection of corrosion as well as detailed inforrfiation about the corrosion products including ccmplex permLttivity profiles. A variety of aircraft-relevant samples - including al ^Lnum, steel and composites in riveted form, curved and under stress - will ^ evaluated using this and corroborating techniques in accelerated corrosive atmospheric environments. The ability of the techniques to detect corrosion early will te evaluated. The inforriation on the surface growths obtained from resonant analysis will ^ correlated with structural and kLnetic inforrnation to determine the most likely corrosion products and when they are most likely to cause significant damage.