What is the main purpose of MPI?

The primary purpose of Magnetic Particle Inspection (MPI) is to identify surface and near-surface defects in ferromagnetic materials. This non-destructive testing method takes advantage of the magnetic properties of ferromagnetic materials, such as iron, nickel, and cobalt. When these materials are magnetized, any surface or near-surface discontinuities, like cracks or voids, will disrupt the magnetic field. This disruption causes magnetic particles to cluster at the site of the defect, making it visible to the inspector.

MPI is particularly effective for detecting issues that occur in the surface layer of materials, which can be critical for ensuring the structural integrity of components used in various industries, particularly in aerospace, automotive, and manufacturing. This method is both quick and efficient, allowing inspectors to perform thorough examinations without damaging the components being tested.

In comparison, the other options focus on entirely different testing methods or purposes—such as assessing electrical failures or thermal properties, which are not relevant to the capabilities of MPI. Additionally, chemical analysis pertains to evaluating material composition rather than detecting physical defects, again outside the scope of magnetic particle inspection.