Which type of magnetic particles is most effective for MPT?

The effectiveness of magnetic particles in Magnetic Particle Testing (MPT) is significantly enhanced when both dry and wet magnetic particles are utilized. Each type of particle has unique advantages that contribute to the overall testing process.

Wet magnetic particles, suspended in a liquid medium, are particularly effective for detecting surface and near-surface discontinuities. The liquid suspension allows for even distribution of the particles over the test surface, enhancing the visibility of flux leakage patterns created by defects. They can adhere better to complex geometries, ensuring comprehensive coverage of the area being inspected.

Dry magnetic particles, on the other hand, provide an advantage in specific applications such as inspecting components where a dry method is more practical or where excess fluid could cause problems. They are also easier to clean after inspection.

By combining both types, inspectors can leverage the strengths of each while compensating for the limitations of the other, thereby improving sensitivity and reliability in detecting discontinuities during the testing process. This versatility is crucial for ensuring thorough inspections across a variety of materials and geometries in industrial applications.