Influence of configurational atomic order on the relative stability of bcc and close-packed structures in Cu-based alloys

We present a study of the influence of atomic order on the relative stability of the bcc and the 18R martensitic structures in a Cu2.96Al0.92Be0.12 crystal. Calorimetric measurements have shown that disorder increases the stability of the 18R phase, contrary to what happens in Cu-Zn-Al alloys for wh...

Descripción completa

Detalles Bibliográficos
Autores: Jurado Cardelús, Mariàngels, Mañosa, Lluís, Planes Vila, Antoni
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1993
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/9906
Acceso en línea:https://hdl.handle.net/2445/9906
Access Level:acceso abierto
Palabra clave:Transformacions de fase (Física estadística)
Diagrames de fase
Transformacions martensítiques
Phase transformations (Statistical physics)
Phase diagrams
Martensitic transformations
Descripción
Sumario:We present a study of the influence of atomic order on the relative stability of the bcc and the 18R martensitic structures in a Cu2.96Al0.92Be0.12 crystal. Calorimetric measurements have shown that disorder increases the stability of the 18R phase, contrary to what happens in Cu-Zn-Al alloys for which it is the bcc phase that is stabilized by disordering the system. This different behavior has been explained in terms of a model recently reported. We have also proved that the entropy change at the martensitic transition is independent of the state of atomic order of the crystal, as predicted theoretically. Our results suggest that differences in the vibrational spectrum of the crystal due to different states of atomic order must be equal in the bcc and in the close-packed phases.