Computer simulation study of the structure of twin boundaries and twinning dislocations in body centred cubic metals

Conference · Thu Jan 01 00:00:00 EST 1976 · Nucl. Metall.; (United States)

OSTI ID:7246573

Bristowe, P D; Crocker, A G

The structures of (112) twin boundaries and of boundary steps or twinning dislocations in bcc crystals have been studied using computer simulation methods and interatomic potentials representing iron, molybdenum and tungsten. Two distinct boundary structures were found to be stable or metastable in the models used. These were the conventional twin interface defined by a reflection orientation relation and a twin in which the boundary consisted of a layer of cells which project on the (1 anti 1 0) plane as interlocking isosceles triangles. This result implies that in at least some bcc metals the perfect twinning dislocation of Burgers vector 1/6 (anti 1 anti 1 1) is likely to be dissociated into two partials, each with Burgers vector 1/12 (anti 1 anti 1 1). Atomistic calculations have been used to determine the core structures of these partials and also their separations. Various methods of presenting the results have been considered. The implications of these results are described especially in relation to fracture and current nucleation and growth mechanisms for twins.

• Research Organization: Univ. of Surrey, Guildford, Eng.
• OSTI ID: 7246573
• Journal Information: Nucl. Metall.; (United States), Vol. 20; Conference: Conference on computer simulation for materials applications, Gaithersburg, MD, USA, 19 Apr 1976; Other Information: See CONF-760421--P1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IRON
TWINNING
MOLYBDENUM
TUNGSTEN
COMPUTER CALCULATIONS
BCC LATTICES
BURGERS VECTOR
CRYSTAL LATTICES
DISLOCATIONS
GRAIN BOUNDARIES
ORIENTATION
REFLECTION
SIMULATION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CUBIC LATTICES
ELEMENTS
LINE DEFECTS
METALS
MICROSTRUCTURE
REFRACTORY METALS
TRANSITION ELEMENTS
360102* - Metals & Alloys- Structure & Phase Studies