Magnetic Particle NDT Testing
Magnetic particle Inspection (MPI) is a non-destructive testing (NDT) process for detecting surface and slightly subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys. American Metal Testing uses this process for NDT.
Mag particle testing puts a magnetic field into the part and the part can be magnetized by direct or indirect magnetization. Direct magnetization passes electric current through the test object and a magnetic field is formed in the material. Indirect magnetization occurs when no electric current is passed through the test object, but a magnetic field is applied from an outside source. The magnetic lines of force are perpendicular to the direction of the electric current, which may be either alternating current or some form of direct current.
The presence of a surface or subsurface discontinuity in the material allows magnetic flux to leak, since air cannot support as much magnetic field per unit volume as metals. Ferrous particles are then applied to the part. The particles may be dry or in a wet suspension. If an area of flux leakage is present, the particles will be attracted to this area. The particles will build up at the area of leakage and form what is known as an indication. The indication can then be evaluated to determine what it is, what may have caused it, and what action should be taken, if any.
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How we prove your products meet standards?
We start by understanding your quality standards. We comply with ASTM standards and we are NADCAP accredited for Flourescent Penetrant, Magnetic Particle and Radiography Film. The standards that your parts need to meet will determine the process that we use. Below are the processess that we specialize in perfoming.