Which material can be assessed using magnetic particle testing?

Magnetic particle testing is a non-destructive testing method specifically designed for ferromagnetic materials. This technique exploits the property of ferromagnetic substances to become magnetized when exposed to a magnetic field, allowing for the detection of surface and slightly subsurface discontinuities such as cracks, voids, and inclusions.

In this process, a magnetic field is induced in the material, and ferrous particles are applied. If there are any surface defects, the magnetic field will be disrupted, causing the particles to accumulate at the flaw, making it visible under appropriate lighting conditions.

Non-ferromagnetic materials do not possess the required magnetic properties to be tested using this method. Similarly, while composite materials and metals can have their various properties assessed through other techniques, they do not benefit from magnetic particle testing. This specificity to ferromagnetic materials highlights why the selected answer is the best choice regarding the applicability of magnetic particle testing.