Microwave Detection for the Surface Corrosion and Cracks in Metals

摘要

The use of microwave and millimeter wave non-destructive testing methods utilizing open ended rectangular waveguide sensors has shown great potential for detecting the surface corrosion and cracks in metals. The results show that variations in the magnitude as well as the phase of the presence of rust. Microwave images of rusted speciments, obtained at 24GHz,are presented. In the absence of a crack, the metal surface is seen as a relatively good short circuit load that will not generate any higher order modes. However, in the presence of a crack higher order modes are generated which in turn change the reflection properties at the waveguide aperture. The experimental and theoretical foundations of the technique is given.