| Autor: |
Choi, Nuri, Taheriniya, Shabnam, Yang, Sangsun, Esin, Vladimir A., Yu, Ji Hun, Lee, Jai-Sung, Wilde, Gerhard, Divinski, Sergiy V. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 12/28/2022, Vol. 132 Issue 24, p1-14, 14p |
| Abstrakt: |
Grain boundary diffusion in an additively manufactured equiatomic CoCrFeMnNi high-entropy alloy is systematically investigated at 500 K under the so-called C-type kinetic conditions when bulk diffusion is completely frozen. In the as-manufactured state, general (random) grain boundaries are found to be characterized by orders-of-magnitude enhanced diffusivities and a non-equilibrium segregation of (dominantly) Mn atoms. These features are explained in terms of a non-equilibrium state of grain boundaries after rapid solidification. The grain boundary diffusion rates are found to be almost independent on the scanning/building strategy used for the specimen's manufacturing, despite pronounced microstructure differences. Grain boundary migration during diffusion annealing turned out to preserve the non-equilibrium state of the interfaces due to continuous consumption of the processing-induced defects by moving boundaries. Whereas the kinetic "non-equilibrium" state of the interfaces relaxes after annealing at 773 K, the non-equilibrium segregation is retained, being further accompanied by a nano-scale phase decomposition at the grain boundaries. The generality of the findings for additively manufactured materials is discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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