Magnetic Particle Testing (MP)

The Magnetic Particle Testing (MP) is also used by VAIC inspectors, which is a nondestructive examination (NDE) technique used to detect surface and slightly subsurface flaws in most ferromagnetic materials such as iron, nickel, and cobalt, and some of their alloys. Because it does not necessitate the degree of surface preparation required by other nondestructive test methods, conducting MPT is relatively fast and easy. This has made it one of the more commonly utilized NDE techniques.
VAIC works in this method by inducing a magnetic field in the component tested. If a surface or near- surface flaw is present, the magnetic flux is distorted and ‘leaks’ around the flaw. By dusting the surface of the tested item with fine magnetic particles such as ferrous iron filings, (applied either dry or suspended in liquid), the particles will be attracted to the area of the flux leakage creating a visible indication of the defect. The indication can be evaluated by the operator to determine what it is, what may have caused it, and what action should be taken, if any.