Consideration of multi-coil type magnetizer for detection of omnidirectional crack in magnetic particle testing

Issue title: Proceedings from the 17th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2015)

Guest editors: Fumio Kojima, Futoshi Kobayashi and Hiroyuki Nakamoto

Article type: Research Article

Authors: Fukuoka, Katsuhiro^{a; *} | Noma, Shota^a | Kobayashi, Masaki^b | Ozaki, Tomohiro^b | Oikawa, Yoshiro^b

Affiliations: [a] The University of Shiga Prefecture, Hikone, Shiga, Japan | [b] Development Department Denshijiki Industry Co., Tokyo, Japan

Correspondence: [*] Corresponding author: Katsuhiro Fukuoka, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533, Japan. Tel.: +81 749 28 9554; Fax: +81 749 28 9554; E-mail:fukuoka.k@usp.ac.jp

Abstract: In a rotating-magnetic-field-type magnetizer using a three-pole (three-phase) coil, omnidirectional cracks can be detected via a single test. However, the rotating magnetic field ultimately experiences non-homogeneous distribution in an area far from the centre of the magnetizer. In this study, a multi-coil-type magnetizer that widely obtains uniform rotating magnetic fields was hence developed. Distributions of rotating magnetic flux densities in test object were evaluated using finite-element analysis, and the utility of the multi-coil was confirmed. In addition, the technique for omnidirectional magnetization on whole surfaces of 3D-shaped test object was considered via implementation of the subject multi-coil magnetizer.

Keywords: Magnetic particle testing, rotating magnetic field, multi coil, omnidirectional magnetization, finite element method

DOI: 10.3233/JAE-162174

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1537-1543, 2016