2. Examination of breaks

Mechanical parts that break, either in service or during manufacture (semi-finished products or blanks) have fracture surfaces that reflect both their metallurgical structure and the conditions of use or manufacture. Fractures are also produced in the laboratory, either after notching or on a pre-existing crack: this is a method of revealing the structure.

The reading of fractures, whether natural or induced, always provides valuable information about the metal, the fracture initiation and the stress conditions [M 4 120] ,