Fracture Surface Analysis

When a metal (or in fact any other object) fails or breaks a surface is created by that fracturing process. In fact, usually two identical, mirror image surfaces are created by a fracturing process. Analysis of the fractured surface can be conducted at several levels. Visual examination can give clues or evidence of the fracture mechanism or process (fracture mode). Visual examination of the macroscopic fracture features can give a strong indication of the fracturing process. This is the science (or art) of fractography. Fractography can give a variety of clues or evidence (macroscopic fingerprints) of the fracture process.

Fracture surface evaluation using the SEM is a common practice in metallurgical failure analysis. Some of the common fracture modes are:

1) Cleavage

2) Dimple Rupture

3) Intergranular

4) Metal Fatigue

5) Progressive Stepwise Fracture

6) Quasi-Cleavage

7) Transgranular