Magnetic Particle Inspection
Reliable detection for safer, stronger parts
Magnetic Particle Inspection (MPI) is a non-destructive testing (NDT) method used to detect surface and near-surface flaws in ferromagnetic materials such as iron, steel, nickel, and some alloys. It can detect surface cracks, near-surface cracks, seams, laps, and inclusions, and fatigue and stress cracks.
Process Overview
- Magnetization
The part is magnetized using a magnetic field (either AC or DC). - Application of magnetic particles
Fine iron particles—either dry powder or suspended in liquid (often fluorescent)—are applied to the surface. - Defect indication
If there is a crack, seam, or other discontinuity, it disrupts the magnetic field and creates a leakage field. The magnetic particles are attracted to this leakage and gather at the defect, making it visible. - Inspection
The inspector visually examines the part (under normal light or UV light for fluorescent particles).
Advantages of Magnetic Particle Inspection
- Magnetic Particle Inspection combines speed and high sensitivity, allowing defects to be identified in real time as indications form directly at the flaw location, without complex
- Fast and relatively inexpensive: MPI provides immediate results with minimal setup and equipment costs, making it an efficient inspection method for both field and shop applications.
- Highly sensitive to small surface cracks: The method is capable of detecting very fine surface and near-surface discontinuities that may not be visible to the naked eye.
- Immediate visual results: Defects are clearly indicated by the accumulation of magnetic particles, allowing inspectors to quickly locate and evaluate flaws without additional analysis.
Calico offers several other application-specific Magnetic Particle Inspection.
For additional details, please contact us.
(704) 483-2202