Brittle to ductile transition to cleavage fracture: Progress report, April 1-November 30, 1987

Technical Report · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5532281

Argon, A S

The brittle-to-ductile transition in cleavage fracture in single crystals is being studied both experimentally and theoretically as the key problem in such fracture transitions exhibited by intrinsically brittle (cleavable) polycrystalline solids. The intrinsic process that governs the transition is thermally assisted dislocation emission from the tips of atomically sharp cleavage cracks at the verge of propagation, which then provide effective crack tip shielding and blunting. All other phenomena known to influence the transition in fracture, such as shielding provided through the polarization of free dislocations in the distant field, micro-crack initiation, etc., are identified as extrinsic processes that merely shift the basic transition to lower temperatures or higher crack velocities, or consider formation of cracks with the required velocity for cleavage propagation.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Mechanical Engineering
• DOE Contract Number: FG02-87ER45294
• OSTI ID: 5532281
• Report Number(s): DOE/ER/45294-T1; ON: DE88004074
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BRITTLE-DUCTILE TRANSITIONS
RESEARCH PROGRAMS
CARBON ADDITIONS
CRACK PROPAGATION
CRACKS
DISLOCATIONS
FRACTURES
IRON ADDITIONS
IRON BASE ALLOYS
MAGNESIUM OXIDES
MONOCRYSTALS
PROGRESS REPORT
SILICON
SILICON ALLOYS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DOCUMENT TYPES
ELEMENTS
FAILURES
IRON ALLOYS
LINE DEFECTS
MAGNESIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SEMIMETALS
360103* - Metals & Alloys- Mechanical Properties
360203 - Ceramics
Cermets
& Refractories- Mechanical Properties