What are the two primary methods of magnetizing a test specimen in Magnetic Particle Testing?

The two primary methods of magnetizing a test specimen in Magnetic Particle Testing are direct magnetization and indirect magnetization.

Direct magnetization involves applying a magnetic field directly across the test piece, often through the use of electrical currents. This method is typically effective for testing ferro-magnetic materials and allows for the detection of surface and near-surface discontinuities.

Indirect magnetization, on the other hand, involves establishing a magnetic field around the test specimen rather than directly passing the current through it. This method can be conducted using external coils or magnetic yokes and is particularly useful for components with complex geometries or when direct access for magnetizing is limited.

Understanding these two methods is crucial for effectively conducting magnetic particle testing, as each method has its specific applications depending on the material and the configuration of the specimen being tested.