Evolution and degradation of microstructure of nickel based alloys during directional solidification, heat treatments and creep
| Project start: | 01.01.2007 |
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| Project end: | 31.12.2009 |
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| Programme: | VEGA |
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| Project number: | 2/7085/27 |
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| Institute position in the project: | The only one project investigator |
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| Project leader: | Juraj Lapin |
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This project is focused on a fundamental research of single crystalline nickel based superalloys and multiphase nickel based intermetallic alloys for high-temperature structural applications. Emphasis is given to achieving new original knowledge about evolution and degradation of microstructure during directional solidification, heat treatments and creep exposure. Expected experimental and theoretical results will contribute to a deeper understanding of the growth of single crystalline nickel based superalloys on planar, cellular and dendritic solid-liquid interfaces. A detailed microsegregation analysis of alloying elements during solidification will result in a definition of critical growth parameters leading to convection and formation of defect structure. New results about coarsening kinetics of precipitates during isothermal annealing and the growth of rafted structure during creep exposure will be obtained. The effect of degraded microstructure on mechanical properties will be defined. For multiphase nickel-based intermetallic alloys with NiAl primary solidification phase, micro and macrosegregation behavior of alloying elements will be determined. In addition, the effect of coexisting phases on initiation and propagation of plastic deformation during mechanical loading at room and higher temperatures will be defined. Expected fundamental knowledge will contribute significantly to optimization of solidification and heat treatment processes for the studied alloys which will lead to tailored microstructure and mechanical properties for specific structural applications.
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