What is the typical magnetization technique used in MPI?

The typical magnetization technique used in Magnetic Particle Inspection (MPI) involves both direct and indirect magnetization methods. This approach is favored because each method has its unique advantages in detecting surface and near-surface discontinuities.

Direct magnetization involves applying the magnetic field through the object, creating a magnetic field where the direction of the current supply is aligned with the part. This method is particularly effective for parts that are small and can be easily magnetized.

Indirect magnetization, on the other hand, applies the magnetic field in a way that allows for greater flexibility, such as using a magnetic yoke or a coil. This method is advantageous for larger components or complex geometries that may not be practical to magnetize directly.

By utilizing both methods, inspectors can achieve a more comprehensive evaluation of the object's integrity, leading to increased sensitivity in detecting flaws. This dual approach is crucial in ensuring that inspections meet the necessary standards for safety and reliability in various applications, such as aerospace, automotive, and manufacturing industries.