Fracture
- For fractures in bones, see Fracture (bone).
| Mechanical failure modes |
|---|
| Buckling |
| Corrosion |
| Creep |
| Fatigue |
| Fracture |
| Melting |
| Wear |
A fracture is the separation of a body into two, or more, pieces under the action of stress.
The word fracture is often applied to bones of living creatures, or to crystals or crystalline materials, such as gemstones or metal. Sometimes, in crystalline materials, individual crystals fracture without the body actually separating into two or more pieces. Depending on the substance which is fractured, a fracture reduces strength (most substances) or inhibits transmission of light (optical crystals).
A detailed understanding of how fracture occurs in materials requires the study of fracture mechanics.
Table of contents |
Types of fracture
The orientation of any crystals in a material can strongly affect its fracture response. The character of a fracture is mainly seen by the type of stress which causes it.
Brittle fracture
In brittle fracture, no plastic deformation takes place before fracture. In brittle single crystals, [[cleavage (crystal)cleavage fracture|]] occurs as the result of tensile stress acting normal to any of a crystal's cleavage planes. In amorphous solids, by contrast, a lack of crystallinity means that any direction may be considered a cleavage plane; the result is a conchoidal fracture, with cracks proceeding normal to the applied tension.
Ductile fracture
In ductile fracture, extensive plastic deformation takes place before fracture. Similarly, shear fracture arises from the action of shear stress and slip in crystals.
Bibliography
- Dieter, G. E. (1988) Mechanical Metallurgy ISBN 0071004068
- A. Garcimartin, A. Guarino, L. Bellon and S. Cilberto (1997) " Statistical Properties of Fracture Precursors ". Physical Review Letters, 79, 3202 (1997)
Categories: Materials science