Magnetic Particle

Magnetic Particles Inspection is one of the most widely used in NDT methods, quite economical because it is easy to do and faster than UT and RT, can detect surface and subsurface defects in ferrous materials, moderately portable, and fairly easy to interpret. MPI uses magnetic fields and small magnetic particles to detect flaws in components, which must be made of ferromagnetic material such as iron, nickel, cobalt, or some of their alloys. Magnetization of the material being inspected is done in three different ways: using a permanent or electromagnet, using magnetic field from a wire with current running through it, and using electric current running through the part itself. It is used to detect cracks seen 45 to 90 degrees to the magnetic flux lines. EII utilizes visible powder and florescent magnetic particle procedures as required by applicable code or specification. After the inspection is complete, the part is demagnetized to avoid interference with sensitive electronic instrumentation.