Electron-microscope observation of crack propagation and a dislocation model of fracture

Conference · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5829674

Ohr, S M

This paper describes electron microscope observations of the emission and distribution of dislocations at the crack tip during in-situ tensile deformation. The most interesting result has been the direct observation of a dislocation-free zone (DFZ) between the crack tip and the plastic zone. In order to understand the origin of the DFZ, a dislocation theory of fracture has been developed and the critical stress intensity factor K/sub g/ for the dislocation generation at the crack tip is proposed as the definition for the condition for crack tip deformation.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5829674
• Report Number(s): CONF-830680-2; ON: DE83014623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
BRITTLE-DUCTILE TRANSITIONS
COPPER
CRACK PROPAGATION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DEFORMATION
DISLOCATIONS
ELECTRON MICROSCOPY
ELEMENTS
FRACTURE PROPERTIES
LINE DEFECTS
MECHANICAL PROPERTIES
METALS
MICROSCOPY
MOLYBDENUM
NIOBIUM
STRESS INTENSITY FACTORS
TRANSITION ELEMENTS