What is the effect of decreased permeability on eddy current penetration?

Decreased permeability in a material leads to a reduction in eddy current penetration. Permeability refers to the ability of a material to support the formation of magnetic fields within itself. When the permeability is lower, the magnetic field generated by the eddy currents is less able to penetrate deeply into the material. This is because a material with decreased permeability creates greater opposition to the magnetic field lines, causing the eddy currents to remain more concentrated at the surface.

In Eddy Current Testing, the effectiveness of detecting flaws in materials is highly dependent on how well eddy currents can penetrate those materials. As penetration decreases due to lower permeability, the ability to detect subsurface defects diminishes, making the testing less effective. Therefore, understanding the relationship between permeability and eddy current penetration is critical for effective non-destructive testing using this method.