Magnetic Particle Inspection (MT)

Magnetic particle inspection is used for detecting surface and near surface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys, by applying a magnetic field and magnetic particles to detect of magnetic flux leakage. The magnetic particles are drawn, and held to the surface of the part by the flux leakage which creates a visible indication of any discontinuities.

  • Economical
  • Simple and fast
  • Extremely portable
  • Can even work through thin layers of paint
  • Large surface areas of complex parts can be inspected rapidly
  • Best at detecting fine, shallow surface cracks
  • Only ferromagnetic materials can be inspected
  • Requires relatively smooth surface
  • Large currents are needed for larger parts
  • Demagnetization and post cleaning is usually necessary
  • Only detects surface and near surface discontinuities
  • Thick paint and or nonmagnetic coverings adversely affect sensitivity