Deformation fracture

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The ductile fracture (also ductile fracture or Tough break ) is also called because of its microscopic appearance honeycomb failure called. This break only occurs after a major plastic deformation. A strong constriction in the area of ​​the fracture zone is characteristic of this fracture. However, this is not the case if it is a residual force fracture, since here only a very small area in relation to the entire fracture surface is exposed to rapid and highly plasticized deformation. At room temperature and without any weakening of the grain boundaries (e.g. due to precipitation or corrosion), only a transcrystalline fracture (i.e. through the grain) occurs.

ductile rupture

The ductile force fracture is favored by high temperature, a largely uniaxial stress state , which can also result from thin-walled components, and by soft materials (e.g. copper). In the case of ductile forced fractures, which are subjected to tensile loads until they break, tensile honeycombs (see illustration) as well as separation of individual phases and carbide inclusions can be identified.

The honeycombs that can be seen in the picture are generally caused by local constriction between inclusions / precipitations and the matrix material as well as pores and micro- cavities . The local separation of the particles from the matrix material widen more and more in the direction of the external stress to form ellipsoidal cavities. A large number of these cavities arise and expand. If a certain critical number of cavities is exceeded, the webs between the cavities shear off and the honeycomb structure typical of ductile forced fracture becomes visible.

Other types of fractures

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