Remelting induced fully-equiaxed microstructures with anomalous eutectics in the additive manufactured Ni32Co30Cr10Fe10Al18 eutectic high-entropy alloy

Large columnar grains with epitaxial growth are commonly obtained in the additive manufacturing of alloys, resulting in anisotropic mechanical properties and even hot-tearing cracks. Here, we demonstrate a new approach via remelting-introduced columnar-to-equiaxed transformation to promote the forma-tion of fully-equiaxed microstructures in the additive manufacturing of Ni32Co30Cr10Fe10Al18 eutectic high-entropy alloy. Our present work displays promising isotropic mechanical properties with a superior com-bination of strength and ductility, compared to conventional as-cast and other as-printed eutectic high-entropy alloys. This novel finding could be applicable to the additive manufacturing of other eutectic systems for equiaxed microstructure control and performance optimization. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates a new approach to promote the formation of fully-equiaxed microstructures in the additive manufacturing of Ni32Co30Cr10Fe10Al18 eutectic high-entropy alloy through remelting-induced columnar-to-equiaxed transformation. The research shows promising isotropic mechanical properties and a superior combination of strength and ductility compared to conventional and other printed high-entropy alloys.