1. Fracture mechanisms

1.1 Brittle fractures, ductile fractures

Metals, which are made up of crystals, essentially break in two ways: either by the crystallographic planes moving apart, known as cleavage fracture, or by sliding along these planes, separating the part in two when their amplitudes become excessive (figure 1 ), known as shear fracture.

When the grain boundaries at the intersection of two crystals are less resistant than the crystals themselves, the fracture follows the grain boundaries and is referred to as intergranular fracture.

Cleavage fractures are brittle, while shear fractures are ductile. However, there is a risk of confusion, in...