A first-principles study on influence of elemental doping on mechanical properties in nickel-based single-crystal superalloys 镍基单晶高温合金元素掺杂对力学性能影响的第一性原理研究
The mechanical properties and thermodynamic stability of nickel-based single-crystal superalloys are largely dependent on the charateristics of the precipitated phase interface. In this work, density functional theory(DFT) is utilized to investigate the influence of alloying elements, specially Co,...
| Autores: | , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/407700 |
| Acceso en línea: | http://hdl.handle.net/10261/407700 |
| Access Level: | acceso abierto |
| Palabra clave: | Nickel-based single-crystal superalloys γ/γ′ interface Mechanical propierties Electronic structure First-principles calculations |
| Sumario: | The mechanical properties and thermodynamic stability of nickel-based single-crystal superalloys are largely dependent on the charateristics of the precipitated phase interface. In this work, density functional theory(DFT) is utilized to investigate the influence of alloying elements, specially Co, Cr, Mo, W, Re and Ta, on the mechanical properties of γ-Ni/γ′-NiAl interface. Following a convergence analysis to the optimal computational model,our findings reveal that Re and W exhibit the most significant strengthening effects within both the γ and γ′ phases. Notably, Re stands out for its substantial enhancement of Young’s modulus(27 GPa and 11 GPa) and shear modulus(16 GPa and 6 GPa) in the γ and γ′ phases, respectively, while Ta demonstrates a unique proficiency in augmenting the bulk modulus of 21 GPa and 14 GPa in the γ and γ′ phases, respectively. Analysis of interfacial tensile properties indicates that the Re-doped system exhibit the highest ideal tensile strength(approximately 25 GPa) and deformation energy(approximately 1.84 J·m) . Furthermore, the strengthening impact of alloying elements on interface tensile properties diminishes in the order:Re>W>Cr>Mo>Ta>Co>undoped. Analyses of differential charge density and density of states reveal that the strengthening mechanisms of theses alloying elements are attributable to the augmentation in the chemical bonding strength between doped atoms and their nearest-neighbouring host atoms. Electron orbital characteristics indicate that these alloying elements contribute to retarding interfacial fracture by maintaining local structural stability. A series of results provide ideas for the development of novel nickel-based single-crystal superalloys. |
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