On the micromechanics of brittle fracture

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Acta Metallurgica; (USA)

OSTI ID:5659421

Jokl, M L ^[1]; Vitek, V; McMahon, Jr, C J ^[2]; Burgers, P ^[3]

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1. Barnwell Industries, Inc., Fairlawn, NJ (US)
2. Pennsylvania Univ., Philadelphia, PA (USA). Dept. of Materials Science and Engineering
3. Hibbitt, Karlsson and Sorensen, Providence, RI (USA)

The response of a deformable solid, in which dislocations are assumed to be highly mobile, to the presence of a loaded crack has been examined, and two cases have been considered. In the first case, that of a crack which pre-exists at zero load, it was confirmed that dislocation emission from the crack tip always precludes brittle crack propagation. In the second case, a microcrack is injected into the loaded deformable solid, for example, due to the cracking of a brittle inclusion. In this case simultaneous dislocation emission and brittle crack propagation can occur, depending on the cohesive energy and the dislocation mobility. Both cases have been studied dynamically, assuming fast moving dislocations, and the effect of the presence of dislocations upon the crack-tip field was fully taken into account. The implications of these results for understanding the brittle-ductile transition and impurity-induced intergranular embrittlement are discussed.

• OSTI ID: 5659421
• Journal Information: Acta Metallurgica; (USA), Journal Name: Acta Metallurgica; (USA) Vol. 37:1; ISSN 0001-6160; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
BRITTLE-DUCTILE TRANSITIONS
CHEMICAL REACTIONS
CORROSION
CRACK PROPAGATION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
FRACTURE MECHANICS
IMPURITIES
INTERGRANULAR CORROSION
LINE DEFECTS
MECHANICS
SOLIDS