Magnetic Particle Test (MT)
This NDT method is accomplished by inducing a magnetic field in a
ferromagnetic material and then dusting the surface with iron
particles (either dry or suspended in liquid).
Surface and near-surface flaws produce magnetic poles or distort the
magnetic field in such a way that the iron particles are attracted and
concentrated. This produces a visible indication of defect on the
surface of the material. Therefore, the method is most applicable for
detecting the surface or sub-surface defects.
MT can be applied in various types depending on the applications
required. It could be wet, powder or fluorescent.