brittleness
Learn about this topic in these articles:
ceramics
- In ceramic composition and properties: Brittleness
Unlike most metals, nearly all ceramics are brittle at room temperature; i.e., when subjected to tension, they fail suddenly, with little or no plastic deformation prior to fracture. Metals, on the other hand, are ductile (that is, they deform and bend when subjected to…
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glass
- In industrial glass: Elasticity and plasticity
…observed; instead, glass failure is brittle—that is, the glass object fractures suddenly and completely. This behaviour can be explained by the atomic structure of a glassy solid. Since the atoms in molten glass are essentially frozen in their amorphous order upon cooling, they do not orient themselves into the sheets…
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linearly elastic solids
- In deformation and flow
…such elastic solids exhibit either brittleness (in which the internal elastic forces are broken down) or ductility (in which certain internal mechanisms permit shearing displacements to occur within the atomic structure). For materials with a crystalline structure, these shearing displacements are usually associated with defects within the crystal lattice. Such…
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materials testing
- In materials testing: Impact test
…at different temperatures, becoming very brittle when cold. Tests have shown that the decrease in material strength and elasticity is often quite abrupt at a certain temperature, which is called the transition temperature for that material. Designers always specify a material that possesses a transition temperature well below the range…
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minerals
- In mineral: Tenacity
…is removed (talc is flexible); brittle, showing little or no resistance to breakage, and as such separating into fragments under the blow of a hammer or when cut by a knife (most silicate minerals are brittle); and elastic, capable of being bent or pulled out of shape but returning to…
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quasicrystals
- In quasicrystal: Mechanical properties
Quasicrystals are exceptionally brittle. They have few dislocations, and those present have low mobility. Since metals bend by creating and moving dislocations, the near absence of dislocation motion causes brittleness. On the positive side, the difficulty of moving dislocations makes quasicrystals extremely hard. They strongly resist deformation. This…
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steel
- In steel: Effects of heat-treating
…is the hardest and most brittle form of steel. Tempering martensitic steel—i.e., raising its temperature to a point such as 400° C and holding it for a time—decreases the hardness and brittleness and produces a strong and tough steel. Quench-and-temper heat treatments are applied at many different cooling rates, holding…
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