A principle is proposed for applying the a.c. potential drop technique to nondestructive evaluation of a thin layer on a material surface. First, Maxwell's equations are solved to obtain the potential drop on the surface of a layer, where induced electromotive force due to magnetic field caused around the material by the current is treated as one of unknowns. Next, a.c. potential drop is measured for a specimen with a thin layer on its surface. Finally, the inverse problem is analyzed to determine the thickness and the conductivity of the layer, the electromagnetic property of the matrix and the induced electromotive force, where measurements of the potential drop are compared with theoretical computations for a wide range of frequency. It is verified that the present method can be used for the nondestructive evaluation of the thin layer.
|Number of pages||5|
|Journal||American Society of Mechanical Engineers, Applied Mechanics Division, AMD|
|Publication status||Published - 1994 Dec 1|
|Event||Proceedings of the 1994 International Mechanical Engineering Congress and Exposition - Chicago, IL, USA|
Duration: 1994 Nov 6 → 1994 Nov 11
ASJC Scopus subject areas
- Mechanical Engineering