Embrittlement

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Embrittlement is a loss of ductility of a material, making it brittle. Various materials have different mechanisms of embrittlement.

  • Metal-induced embrittlement (MIE) is the embrittlement caused by diffusion of atoms of metal, either solid or liquid, into the material.
  • The primary embrittlement mechanism of plastics is gradual loss of plasticizers, usually by overheating or aging.
  • The primary embrittlement mechanism of asphalt is by oxidation, which is most severe in warmer climates. Asphalt pavement embrittlement can lead to various forms of cracking patterns, including longitudinal, transverse, and block (hexagonal). Asphalt oxidation is related to polymer degradation, as these materials bear similarities in their chemical composition.

Cryogenic embrittlement[edit]

Around cryogenic temperatures plastics and rubbers become brittle, which is known as the embrittlement temperature.

Embrittlement temperatures[1]
Material Temperature [°F] Temperature [°C]
Plastics
ABS −270 −168
Acteal? −300 −184.4
Delrin -275 to -300 -171 to -184
Nylon -275 to -300 -171 to -184
Polytron −300 −184.4
Polypropylene -300 to -310 -184 to -190
Teflon −275 −171
Rubbers
Buna-N −225 −143
EPDM -275 to -300 -171 to -184
Ethylene propylene -275 to -300 -171 to -184
Hycar -210 to -275 -134 to -171
Natural rubber -225 to -275 -143 to -171
Neoprene -225 to -300 -143 to -184
Nitrile -275 to -310 -171 to -190
Nitrile-butadiene (ABS) -250 to -270 -157 to -168
Silicone −300 −184.4
Urethane -275 to -300 -171 to -184
Viton -275 to -300 -171 to -184
Metals
Zinc −200 −129
Steel −40 −40

See also[edit]

References[edit]

  1. ^ Gillespie, LaRoux K. (1999), Deburring and edge finishing handbook, SME, pp. 196–198, ISBN 978-0-87263-501-2.