Non-Destructive Testing (NDT) Practice Test

Which materials can magnetic particle inspection be performed on?

1. Aluminum, Steel, Copper

2. Iron, Nickel, Cobalt

3. Plastic, Rubber, Wood

4. Brass, Zinc, Lead

The correct answer is: Iron, Nickel, Cobalt

Magnetic particle inspection is a non-destructive testing method primarily used for detecting surface and near-surface defects in ferromagnetic materials. The correct choice includes iron, nickel, and cobalt, which are all ferromagnetic metals. These materials can be magnetized, allowing for the indication of any defects on their surfaces through the use of magnetic fields and fine magnetic particles. When a ferromagnetic material is subjected to a magnetic field, any discontinuities or defects in the material can interrupt the magnetic field lines, causing the magnetic particles to accumulate at those points. This makes detection straightforward, as the areas with defects will show a concentration of particles, providing a direct visual indication of where issues lie in the material. In contrast, the other materials listed in the options do not possess ferromagnetic properties. Aluminum, copper, plastic, rubber, wood, brass, zinc, and lead do not get magnetized in the same way. Therefore, magnetic particle inspection is ineffective for these materials, as they cannot support the magnetic fields required for the method to work. Thus, the correct choice reflects the suitability of magnetic particle inspection specifically for iron, nickel, and cobalt, which are ideal candidates for this form of testing.