Novel NDI by use of magneto-optical film

Jinyi Lee, Tetsuo Shoji, Dorian Minkov, Michiaki Ishihara

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


For horizontal magnetization to the surface of a specimen, two large magnetic domains occur in the area of a crack due to the detection of the vertical component of the leakage magnetic field using a MO film. This leads to a lower density of the domain walls in the crack area in comparison with the no crack area. Considering that the intensity of the incident or the reflected light is affected when it passes through a domain wall, the optical permeability changes in the area of the crack. The use of a laser as a light source allows to perform a remote sensing by detecting of a brighter area corresponding to a crack and a darker area corresponding to its surroundings which is based on the behavior of the optical permeability. This paper introduces a novel NDI method using a MO film and a laser, which allows to detect cracks far away from the specimen. The method utilizes AC and DC magnetization and variation of the domain wall density and optical permeability inside the MO film.

Original languageEnglish
Pages (from-to)825-830
Number of pages6
JournalNihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
Issue number619
Publication statusPublished - 1998


  • Defect detection
  • Domain wall
  • Image processing
  • Laser
  • Magneto-optical film
  • Nondestructive inspection
  • Notch

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Novel NDI by use of magneto-optical film'. Together they form a unique fingerprint.

Cite this