1. Non-destructive testing requirements for metals

One characteristic of non-destructive testing of a part is that it provides information on its integrity without altering the properties essential to its conditions of use. The main source of a lack of integrity in a part is the presence of internal discontinuities or cohesion failures in the material, commonly referred to as defects, which result in discontinuities in acoustic, thermal, and electromagnetic properties.

The location of defects in the part is an important factor in the selection and implementation of inspection techniques:

• Surface defects can be detected by magnetic particle inspection, eddy current testing, infrared thermography, and ultrasonic testing.

• Subcutaneous defects (internal defects close to the surface) can be detected by ultrasound, infrared thermography,...