Dimple Rupture

Dimple rupture is a fracture mechanism occurring in metals which fail under conditions of an overload or tearing stress.  Tiny holes, or microvoids, are created in the interior of a piece of metal when the object is subjected to a load.  As more load is applied these microvoids internally gather together and form small void pockets in the metal.  When the edges of the pockets meet, at the metal separates, small "cup-like" features appear (at high magnification) on the fracture surface. The fracture appearance of such a fracture surface is referred to as dimple rupture.

Photograph A is a scanning electron micrograph showing dimple rupture at a magnification of 2500x.

Photograph A Scanning electron micrograph
showing dimple rupture at a magnification of 2500x.

Types of Dimple Rupture:

1) Shear Dimples

2) Tearing Dimples

3) Tensile Dimples