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arXiv · 2310.15046

Preferential Composition during Nucleation and Growth in Multi-Principal Elements Alloys

Saswat Mishra·Alejandro Strachan
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Abstract

The crystallization of complex, concentrated alloys can result in atomic-level short-range order, composition gradients, and phase separation. These features govern the properties of the resulting alloy. While nucleation and growth in single-element metals are well understood, several open questions remain regarding the crystallization of multi-principal component alloys. We use MD to model the crystallization of a five-element, equiatomic alloy modeled after CoCrCuFeNi upon cooling from the melt. Stochastic, homogeneous nucleation results in nuclei with a biased composition distribution, rich in Fe and Co. This deviation from the random sampling of the overall composition is driven by the internal energy and affects nuclei of a wide range of sizes, from tens of atoms all the way to super-critical sizes. This results in short range order and compositional gradients at nanometer scales.

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Saswat Mishra, Alejandro Strachan. 2023-10-23. Preferential Composition during Nucleation and Growth in Multi-Principal Elements Alloys. https://doi.org/10.1063/5.0181330

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