Rapid corrosion detection using 94 GHz millimeter wave technology

Critical aircraft structural components are constantly exposed to harsh environmental conditions, which result in corrosion of the components. Very often, such corrosions are not easily detectable and by the time they become visible, significant time and resources are required to rectify the corrosion. In this paper, we will present a near-field millimeter-wave dual differential probe detection system at 94 GHz to detect corrosion precursor pittingss. The output of the dual differential probe is the coherent difference between the reflection properties of two closely spaced areas on the sample under test. Using this system, we are able to detect and image pittings of as small as 0.6 mm in diameter, at scanning speed of up to 1.2 m/min in real time. Our results show the feasibility of employing a millimeter-wave system in the field of aviation maintenance and checks.