Eddy Current Tomography for Metal Solidification Imaging

Minh H. Pham*, Yingbo Hua*, Neil B. Gray**

*Department of Electrical and Electronic Engineering,

The University of Melbourne, Parkville, Victoria 3052 Australia, E-mail: yhua@ee.mu.oz.au

**G. K. William Co-operative Research Centre for Extractive Metallurgy, Department of Chemical Engineering,

The University of Melbourne, Parkville, Victoria 3052 Australia

Abstract - This paper presents a theoretical framework of imaging the solidification of molten metal inside a pipe by eddy currents. A complete mathematical model is developed which reveals the relationship between the solidification inside the pipe and the scattered field measurable outside the pipe. This model is then exploited to develop a numerical algorithm which is able to quickly reconstruct the geometry of the solidification based on the measured scattered field intensity. This framework not only appears to be the first of its kinds from the metallurgical point of view, but also involves some novel development from the point of view of electromagnetic computations, which includes in particular the Green functions in multiple layered media.

Keywords: eddy current tomography, electromagnetic field, numerical computation, solidification