An eddy current convergence probe with copper core and single detection coil to detect flaws on aluminum plates

Abstract

This study presents an eddy current probe with an excitation current induced by a copper core. The probe consists of a specially designed copper core placed inside an excitation coil to generate an excitation current, and a single detection coil. To compare the flaw detection abilities, copper cores of different shapes (with slits, without slits, hollowed surface, and a plate fitted under the excitation coil) were prepared. Finite element simulations were first conducted using probe models. In the finite element analysis, a strong excitation current was converged at the tip of the copper core for probes having slits and hollows, and a large eddy current intensity was generated on the test piece. Experiments with the probes were then carried out to detect four artificial flaws of different lengths and depths, on an aluminum plate. From the obtained results, the flaws were clearly detected with the probe, and the excellent nature of the hollowed probe, fitted with a plate under the excitation coil, was validated.