Observations of hierarchal grain boundary dislocation structures in (001) symmetric tilt boundaries in gold

Technical Report · Fri Aug 01 04:00:00 EDT 1986

OSTI ID:5352419

Kvam, E P; Balluffi, R W

Molecular statics calculations using pairwise interatomic potentials by Sutton, Vitek and Wang have predicted the existence of a hierarchy of localized edge-type grain boundary dislocations (GBDs) in (001) symmetric tilt boundaries in fcc noble metals. Furthermore, the geometry of these GBDs can be well described by the Structural Unit/GBD model of Sutton and Vitek as extended by Balluffi and Bristowe. In the present work, a search was made for the presence of such a hierarchy in (001) symmetric tilt boundaries in gold by means of transmission electron microscopy. Numerous arrays of various localized GBDs were detected under various conditions of observation in specimens of differing thickness under different imaging conditions. When the present results are combined with results from other investigations, it is concluded that the first four members of the hierarchy have been detected. One GBD array belonging to an appreciably higher order hierarchal member has been found, and it seems likely that higher order members (which became increasingly difficult to detect) also exist. The results provide support for both the calculations and the Structural Unit/GBD model.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Materials Science and Engineering; Liverpool Univ. (UK). Dept. of Metallurgy and Materials Science
• DOE Contract Number: FG02-84ER45116
• OSTI ID: 5352419
• Report Number(s): DOE/ER/45116-13; ON: DE86015729
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELECTRON MICROSCOPY
ELEMENTS
GOLD
GRAIN BOUNDARIES
LINE DEFECTS
METALS
MICROSCOPY
MICROSTRUCTURE
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY