The brittle-to-ductile transition; 1: A cooperative dislocation generation instability
- Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Materials Science and Engineering
Most materials (with the possible exception of f.c.c. metals) exhibit the well-known brittle-to-ductile transition (BDT) with increase in temperature. The variation of the fracture toughness, (K), with temperature is usually gradual in the brittle regime, but a dramatic rapid increase occurs over a narrow temperature range where the sharp crossover from brittle to ductile behavior takes place. The authors describe a new model that explains the dual characteristics of the BDT, namely, the massive dislocation generation at the transition temperature and the strain-rate dependence of this behavior. In the first part, the authors present a statistical mechanics based two-dimensional (2D) model of spontaneous dislocation generation leading to the BDT. The onset of ductile behavior corresponds to a thermally-induced cooperative instability of many small dislocation dipoles in the presence of an applied stress.
- OSTI ID:
- 6918401
- Journal Information:
- Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 31:10; ISSN SCRMEX; ISSN 0956-716X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
BRITTLE-DUCTILE TRANSITIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELEMENTS
LINE DEFECTS
MATHEMATICAL MODELS
METALS
PHYSICAL PROPERTIES
STRESSES
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE