Diffusion-defining atomic-scale spinodal decomposition within nanoprecipitates
| Autor: | Gerald Kothleitner, Georg Haberfehlner, Johannes Taendl, Maria Cecilia Poletti, Bernhard Sonderegger, Angelina Orthacker |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Spinodal decomposition Mechanical Engineering Alloy 02 engineering and technology General Chemistry Crystal structure engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic units Diffusion process Mechanics of Materials Chemical physics Transmission electron microscopy 0103 physical sciences Scanning transmission electron microscopy engineering General Materials Science Diffusion (business) 0210 nano-technology |
| Zdroj: | Nature materials. 17(12) |
| ISSN: | 1476-4660 |
| Popis: | Stoichiometric precipitates owe their fixed composition to an ordered crystal structure. Deviations from that nominal value, however, are encountered at times. Here we investigate composition, structure and diffusion phenomena of ordered precipitates that form during heat treatment in an industrially cast Al-Mg-Sc-Zr alloy system. Experimental investigations based on aberration-corrected scanning transmission electron microscopy and analytical tomography reveal the temporal evolution of precipitate ordering and formation of non-equilibrium structures with unprecedented spatial resolution, supported by thermodynamic calculations and diffusion simulations. This detailed view reveals atomic-scale spinodal decomposition to majorly define the ongoing diffusion process. It is illustrated that even small deviations in composition and ordering can have a considerable impact on a system's evolution, due to the interplay of Gibbs energies, atomic jump activation energies and phase ordering, which may play an important role for multicomponent alloys. |
| Databáze: | OpenAIRE |
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