Engineering atomic-level complexity in high-entropy and complex concentrated alloys

Hyun Seok Oh,Takeshi Egami,Wook Ha Ryu,Sang Jun Kim,Kook Noh Yoon,Fritz Körmann,Cemal Cem Tasan,Yuji Ikeda,Dierk Raabe,Sai Mu,Khorgolkhuu Odbadrakh,Eun Soo Park

doi:10.1038/s41467-019-10012-7

Abstract

Quantitative and well-targeted design of modern alloys is extremely challenging due to their immense compositional space. When considering only 50 elements for compositional blending the number of possible alloys is practically infinite, as is the associated unexplored property realm. In this paper, we present a simple property-targeted quantitative design approach for atomic-level complexity in complex concentrated and high-entropy alloys, based on quantum-mechanically derived atomic-level pressure approximation. It allows identification of the best suited element mix for high solid-solution strengthening using the simple electronegativity difference among the constituent elements. This approach can be used for designing alloys with customized properties, such as a simple binary NiV solid solution whose yield strength exceeds that of the Cantor high-entropy alloy by nearly a factor of two. This study provides general design rules that enable effective utilization of atomic level information to reduce the immense degrees of freedom in compositional space without sacrificing physics-related plausibility.

Highlights

Quantitative and well-targeted design of modern alloys is extremely challenging due to their immense compositional space
We present a simple property-targeted quantitative design approach for concentrated alloys (CCAs) based on quantummechanically derived atomic-level pressure approximation
Here we established an efficient strategy for a property-targeted quantitative atomic-level complexity design of 3d CCAs based on the atomic-level pressure approximation

Summary

Introduction

Quantitative and well-targeted design of modern alloys is extremely challenging due to their immense compositional space. We present a simple property-targeted quantitative design approach for atomic-level complexity in complex concentrated and high-entropy alloys, based on quantum-mechanically derived atomic-level pressure approximation It allows identification of the best suited element mix for high solid-solution strengthening using the simple electronegativity difference among the constituent elements. We numerically identify the relationship between configurational difference in the charge transfer and the macroscopic difference in the charge transfer among the elements, which enables connecting the atomic-level fluctuation and complexity to the macroscopic property of the material It allows establishment of a design recipe which uses elemental information (electronegativity) (Fig. 1b) without explicit electronic structure calculations as an efficient vehicle for more systematic and constitutive structure-property design of CCAs

Methods

Results

Conclusion