The relation between the structure and mechanical properties of a. sigma. = 51 tilt boundary in germanium
A series of Germanium bicrystals containing a 16/sup 0/ (011) tilt boundary has been deformed in high-temperature creep and analyzed by high-resolution lattice-fringe imaging and conventional transmission electron microscopy. Before deformation, the structure of the boundary consists of a linear array of Lomer dislocations. Subgrain boundaries are produced by the deformation and intersect the original grain boundary. Absorption of lattice-dislocations causes the interfacial structure to change along the boundary from one subgrain to another. Deviations from the ..sigma.. = 51 coincidence structure are accommodated by secondary dislocations. The secondary dislocations have non-primitive DSC-Burgers vectors. Upon entering the grain boundary, the deformation-produced lattice dislocations decompose into secondary dislocations. Their motion in the interface is associated with grain boundary migration and grain boundary sliding. However, the latter process could not be identified macroscopically and, therefore, appears to make a much smaller contribution to the total strain than it does in metals. It is also directly shown that screw dislocations with Burgers vector in direction of the tilt axis can pass through the boundary.
- Research Organization:
- Institut fur Geologie und Dynamic der Lithosphare, Universitat Gottingen, Goldschmidt Str. 3, 3400 Gottingen (DE)
- OSTI ID:
- 7128220
- Journal Information:
- Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 36:4; ISSN AMETA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Grain boundary dislocation structures in (001) symmetric tilt boundaries in aluminum
Group representation of bicrystal invariant translations with an application to the topology of secondary grain boundary dislocations
Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
656002 -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CREEP
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DEFORMATION
ELECTRON MICROSCOPY
ELEMENTS
GERMANIUM
GRAIN BOUNDARIES
HIGH TEMPERATURE
IMAGE PROCESSING
MECHANICAL PROPERTIES
METALS
MICROSCOPY
MICROSTRUCTURE
PHASE STUDIES
PROCESSING
TECHNOLOGY ASSESSMENT
THERMODYNAMICS
TRANSMISSION ELECTRON MICROSCOPY