NDE Physics

Non-Destructive Evaluation (NDE) relies on various principles of physics to inspect and analyse materials and structures without causing any damage.
Understanding these physical principles is essential for NDE engineers and inspectors to interpret inspection results accurately. Here are some key physics principles that underpin common NDE techniques:

1. Acoustics and Wave Propagation

Ultrasonic Testing (UT) and Acoustic Emission (AE) rely on the principles of acoustics and wave propagation. Ultrasonic waves are introduced into the material and propagate through it, interacting with internal structures and defects.
The resulting echoes, or acoustic emissions, provide valuable information about the material's condition.

2. Electromagnetism and Eddy Currents

Eddy Current Testing (ECT) and Electromagnetic Testing (ET) utilise electromagnetic principles. Eddy currents are induced in conductive materials by alternating magnetic fields, and changes in the material's electrical conductivity due to defects create detectable signals.

3. Electromagnetic Radiation

Radiography employs X-rays or gamma rays, which are forms of electromagnetic radiation, to create images of the internal structure of objects.
The variation in absorption of these rays provides information about the material's density and potential defects.

4. Magnetism and Magnetic Particles

Magnetic Particle Inspection (MPI) involves the principles of magnetism. The material is magnetised, and magnetic particles are applied to the surface.
These particles are attracted to areas with magnetic flux leakage, indicating surface defects.