What is the purpose of using magnetic particle inspection?

The purpose of using magnetic particle inspection (MPI) is to identify surface and near-surface defects in ferromagnetic materials. This non-destructive testing method relies on the principle that a magnetic field is created in a magnetic material, which can reveal imperfections such as cracks, laps, and inclusions when magnetic particles are applied. The particles are attracted to areas where magnetic flux is interrupted, typically at flaws, making it possible for inspectors to detect and evaluate those defects visually.

In contrast, evaluating material properties, measuring thickness, or ensuring dimensional accuracy involves different methods or techniques not specifically related to MPI. Material properties can be assessed through other non-destructive testing methods, such as ultrasonic testing or radiographic testing. Measuring thickness usually involves techniques like ultrasonic thickness gauging, while ensuring dimensional accuracy is typically done through precision measuring instruments and techniques like calipers or micrometers. Thus, the focus of MPI is singularly aimed at detecting surface and near-surface flaws, which makes identifying defects its primary objective.