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Efecto superelástico en las aleaciones ferrosas policristalinas
1Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579, Japan. omori@material.tohoku.ac.jp
Science (New York, N.Y.)
|July 2, 2011
Resumen
Las aleaciones superelásticas pueden recuperar su forma después de una gran deformación. Las aleaciones de memoria de forma de hierro-manganeso-aluminio-níquel exhiben una tensión superelástica dependiente de la temperatura mínima debido a los efectos magnéticos, lo que permite aplicaciones más amplias.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La metalurgia es la metalurgia.
- Física del estado sólido Física del estado sólido
Sus antecedentes:
- Las aleaciones superelásticas se deforman en gran medida y recuperan su forma tras la eliminación de la tensión.
- La dependencia de altas temperaturas de las tensiones superelásticas limita las aplicaciones prácticas.
- Las aleaciones de hierro-manganeso-aluminio-níquel (Fe-Mn-Al-Ni) se investigan para las propiedades de memoria de forma.
Objetivo del estudio:
- Para investigar la dependencia de la temperatura de la tensión superelástica en aleaciones de memoria de forma Fe-Mn-Al-Ni.
- Para entender el papel de las contribuciones magnéticas en la energía de Gibbs de transformación.
- Evaluar el potencial para aplicaciones en un amplio rango de temperaturas.
Principales métodos:
- Caracterización experimental del comportamiento superelástico en aleaciones policristalinas Fe-Mn-Al-Ni.
- Análisis termodinámico considerando las contribuciones magnéticas a la energía de Gibbs.
- Medición de la variación de la tensión superelástica en un amplio rango de temperaturas.
Principales resultados:
- Las aleaciones Fe-Mn-Al-Ni exhiben una pequeña dependencia de la temperatura de la tensión superelástica.
- Esto se atribuye a un pequeño cambio de entropía de la transformación influenciado por los efectos magnéticos.
- Una composición de aleación mostró una variación de tensión de sólo 0,53 MPa/°C de -196 a 240°C.
Conclusiones:
- La contribución magnética a la energía de Gibbs reduce significativamente la dependencia de la temperatura de la tensión superelástica en las aleaciones Fe-Mn-Al-Ni.
- Estas aleaciones demuestran potencial para aplicaciones que requieren un rendimiento superelástico estable en un amplio espectro de temperaturas.
- Los hallazgos allanan el camino para diseños avanzados de aleaciones de memoria de forma con mayor estabilidad térmica.
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