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Perspectivas de primeros principios sobre fases de óxido inducidas por cromo en NiO
Xiao Peng1,2, Jianmin Chen1,2, Xin Yan1,2
1School of Materials Science and Engineering, Xiangtan University, Xiangtan, 411105, China. cycai@xtu.edu.cn.
Physical chemistry chemical physics : PCCP
|February 4, 2026
Resumen
La segregación de cromo (Cr) en escamas de óxido de níquel (NiO) en aleaciones de Ni-Cr depende del agrupamiento de átomos de Cr. La comprensión de estos mecanismos atómicos mejora la resistencia a la oxidación a altas temperaturas.
Área de la Ciencia:
- Ciencia de los materiales
- Ciencia de superficies
- Ciencia computacional de materiales
Sus antecedentes:
- La oxidación a alta temperatura de las aleaciones de Ni-Cr forma escamas de óxido complejas.
- La comprensión de la segregación de cromo (Cr) y la formación de precipitados es clave para mejorar la resistencia a la oxidación.
Objetivo del estudio:
- Investigar los mecanismos a escala atómica del comportamiento del Cr en las superficies de NiO y en el volumen.
- Elucidar la relación entre la coordinación del Cr y la evolución de la fase de óxido.
Principales métodos:
- Se utilizaron cálculos de teoría de la funcionalización de la densidad (DFT).
- Se investigó el comportamiento del Cr en las superficies NiO(100), (110) y (111) y en el volumen.
Principales resultados:
- El Cr aislado se segrega a las superficies de NiO, estabilizando soluciones sólidas de Ni(Cr)O a través de la unión Cr-O.
- Los pares y cúmulos de Cr migran a la subsuperficie y se agregan en el volumen.
- Esto promueve la nucleación de fases de espinela NiCr2O4 y corindón Cr2O3.
Conclusiones:
- Un mecanismo de segregación de Cr dependiente del tamaño influye en la formación de la escama de óxido.
- Las ideas a escala atómica guían las estrategias para mejorar la resistencia a la oxidación de las aleaciones de Ni-Cr.
Palabras clave:
aleaciones de níquel-cromoóxido de níquelsegregación de cromoresistencia a la oxidaciónteoría de la funcionalización de la densidadMás Videos Relacionados
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