MAGNETIC PARTICLE TESTING

It is the one of the most widely used NDT methods.This method is so fast and relatively easily as it requires least surface preparation when compared to other techniques.the magnetic particle examination method can be applied to detect crack and other defects at the surface and also sub-surface of the material under test, particularly ferromagnetic materials.for example- iron,cobalt and nickel.Types of defects that can be identified by this method are cracks,seams,cold shut,porosity,etc.

PRINCIPAL

This method is a combination of  NDT methods which are visual testing and magnetic flux leakage testing. The principal of this method is magnetic flux leakage or leakage in magnetic field or change in magnetic permeability

ADVANTAGE

1. This method is relatively faster than liquid penetrant testing for the surface defects
2. Indication at subsurface level can also be identified portable equipment's

DISADVANTAGE

1. De magnetization of a part is required after the test
2. We can apply this method only in ferrous material and cannot inspect Non ferrous materials such as aluminium ,stainless steel etc.