Magnetic Particle Inspection (MPI) uses magnetic fields and small magnetic particles (i.e. iron particles) to detect flaws in components. The only requirement from an inspection standpoint is that the component being inspected must be made of a ferromagnetic material such as iron, nickel, cobalt or some of thier alloys.
During Magnetic Particle Inspection the work piece is magnetized. If any defects are on or near the surface, the defects will create a leakage field. The iron particles are suspended in light oil and are applied to the surface of the magnetized part. The particles will be attracted and cluster at the flux leakage fields, thus forming a visible indication that the inspector can detect with ultraviolet light. Magnetic Particle Inspection produces very exact results therefore, PTI staff is able to not only locate part defects, but also accurately assess their degree of severity.