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Deformación plástica con ampliación del pico reversible en el níquel nanocristalino
Zeljka Budrovic1, Helena Van Swygenhoven, Peter M Derlet
1Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
Science (New York, N.Y.)
|April 10, 2004
Resumen
La deformación plástica en el níquel nanocristalino muestra una ampliación reversible del pico, lo que indica que no hay formas de red de dislocación residual. Este hallazgo desafía los modelos tradicionales de plasticidad de los metales y ofrece nuevos conocimientos sobre los materiales nanoestructurados.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La metalurgia es la metalurgia.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- La deformación plástica en metales de grano grueso es típicamente mediada por la dislocación, lo que lleva a redes residuales y cambios irreversibles.
- El ensanchamiento del pico de difracción de rayos X (XRD) es un indicador común de cambios microestructurales durante la deformación plástica.
Objetivo del estudio:
- Para investigar la naturaleza de la deformación plástica en el níquel nanocristalino electrodepositado.
- Para determinar si las redes de dislocación se acumulan durante la deformación en este material.
- Para explorar la reversibilidad de los cambios microestructurales en la descarga.
Principales métodos:
- Análisis del perfil de pico in situ utilizando difracción de rayos X en la fuente de luz suiza.
- Caracterización del níquel nanocristalino bajo deformación plástica.
Principales resultados:
- La deformación plástica del níquel nanocristalino resultó en una ampliación del pico reversible en XRD.
- La reversibilidad observada indica que una red de dislocación residual no se acumula.
- Esto contrasta con el comportamiento de los metales de grano grueso.
Conclusiones:
- El mecanismo de deformación en el níquel nanocristalino electrodepositado difiere de la plasticidad mediada por dislocación tradicional.
- La reversibilidad del ensanchamiento de los picos sugiere una respuesta microstructural única al esfuerzo.
- In situ XRD es una herramienta valiosa para estudiar las relaciones estructura-propiedad en materiales nanoestructurados.
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