Magnetic particle inspection (MPI) is a non-destructive testing method used to detect surface and near-surface flaws in ferromagnetic materials. The process involves magnetizing the object and applying fine magnetic particles, which can be dry or suspended in a liquid. If there are any cracks or defects, the particles will gather at these areas, making them visible under ultraviolet light or with the naked eye. This technique is commonly used in industries such as aerospace, automotive, and manufacturing to ensure the integrity of components. MPI is effective for identifying issues like cracks, seams, and inclusions, helping to maintain safety and quality standards.