INDUCTORS FOR INDUCING FOUCAULT CURRENTS IN METALS TO MODIFY THEIR STRUCTURE AND PROPERTIES

10.25712/ASTU.1811-1416.2026.02.005

Abstract

This paper provides a review of inductor designs used to induce eddy (Foucault) currents in metals in order to modify their structure and properties, and discusses the fundamental principles of induction heating together with the specific features of pulsed electromagnetic treatment. The advantages of eddy‑current processing over conventional electrode‑based electropulsing are analyzed, including its contactless nature, suitability for components with complex geometries, and the absence of surface damage. The main inductor types for alternating and pulsed current are considered: multi‑turn cylindrical spiral coils, flat single‑layer spiral inductors for heating and forming sheet workpieces, and specialized designs for quenching spherical parts and impulse forming of thin sheets described in several patents. Special attention is paid to cooling systems for inductors, including closed‑loop water, air, and oil circuits, as well as combined solutions using fins and thermally conductive materials that ensure efficient heat removal at high current densities. It is shown that, for magnetic‑pulse processing, a combined cooling approach is the most rational, as it ensures reliable inductor operation under repeated high‑energy pulses. The experimental part investigates magnetic‑pulse compression of cylindrical specimens using an external wire inductor; the width of the deformation zone is found to increase with the number of turns while the indentation depth remains nearly unchanged, and the observed buckling pattern agrees well with analytical estimates of the shell’s bending eigenfrequencies. The results demonstrate the interrelation between inductor geometry, pulse parameters, and plastic deformation, providing a basis for rational design of inductors and cooling systems for electromagnetic processing of metals.