Entropy change of martensitic transformations in Cu-based shape-memory alloys

We have investigated the different contributions to the entropy change at the martensitic transition of different families of Cu-based shape-memory alloys. The total entropy change has been obtained through calorimetric measurements. By measuring the evolution of the magnetic susceptibility with tem...

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Detalles Bibliográficos
Autores: Mañosa, Lluís, Planes Vila, Antoni, Ortín, Jordi, 1959-, Martínez Benjamin, Joan Josep
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1993
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/9885
Acceso en línea:https://hdl.handle.net/2445/9885
Access Level:acceso abierto
Palabra clave:Diagrames de fase
Transformacions de fase (Física estadística)
Termodinàmica
Phase diagrams
Phase transformations (Statistical physics)
Thermodynamics
Descripción
Sumario:We have investigated the different contributions to the entropy change at the martensitic transition of different families of Cu-based shape-memory alloys. The total entropy change has been obtained through calorimetric measurements. By measuring the evolution of the magnetic susceptibility with temperature, the entropy change associated with conduction electrons has been evaluated. The contribution of the anharmonic vibrations of the lattice has also been estimated using various parameters associated with the anharmonic behavior of these alloys, collected from the literature. The results found in the present work have been compared to values published for the martensitic transition of group-IV metals. For Cu-based alloys, both electron and anharmonic contributions have been shown to be much smaller than the overall entropy change. This finding demonstrates that the harmonic vibrations of the lattice are the most relevant contribution to the stability of the bcc phase in Cu-based alloys.