DIRECTIONAL BONDING AND ASYMMETRY OF INTERFACIAL STRUCTURE IN INTERMETALLIC TIAL - COMBINED THEORETICAL AND ELECTRON-MICROSCOPY STUDY

Authors
SIEGL R VITEK V INUI H KISHIDA K YAMAGUCHI M
Citation
R. Siegl et al., DIRECTIONAL BONDING AND ASYMMETRY OF INTERFACIAL STRUCTURE IN INTERMETALLIC TIAL - COMBINED THEORETICAL AND ELECTRON-MICROSCOPY STUDY, Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties, 75(5), 1997, pp. 1447-1459
Citations number
33
Categorie Soggetti
Physics, Applied","Material Science","Physics, Condensed Matter","Metallurgy & Metallurigical Engineering
Journal title
Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties → ACNP
ISSN journal
13642804
Volume
75
Issue
5
Year of publication
1997
Pages
1447 - 1459
Database
ISI
SICI code
1364-2804(1997)75:5<1447:DBAAOI>2.0.ZU;2-8
Abstract
An ordered twin boundary in the Ll(0) TiAl alloy has been investigated by computer modelling and high-resolution electron microscopy (HREM). This combined study demonstrates the significance of directional cova lent-type bonding for the interfacial structure. When using the ab-ini tio full-potential linear muffin-tin orbital method the stable structu re exhibits a pronounced asymmetry. This structure is in an excellent agreement with HREM observations. In contrast, calculations employing central-force many-body potentials predict a structure the asymmetry o f which is so small that it is not discernible in the HREM image. The preference for the strongly asymmetric structure can be understood in terms of the covalent d-type bonding between Ti atoms in this alloy.