Faceted Kurdjumov-Sachs interface-induced slip continuity in the eutectic high-entropy alloy, AlCoCrFeNi_2.1

Ting Xiong^1,2，Wenfan Yang^1,2，Shijian Zheng^1,3，Zhaorui Liu^4,5，Yiping Lu⁶，Ruifeng Zhang^4,5，Yangtao Zhou¹，Xiaohong Shao¹，Bo Zhang¹，Jun Wang⁷，Fuxing Yin³，Peter K.Liaw⁸，Xiuliang Ma^1,9

1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences2. School of Material Science and Engineering, University of Science and Technology of China3. Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology4. School of Materials Science and Engineering, Beihang University5. Center for Integrated Computational Materials Engineering (International Research Institute for Multidisciplinary Science) and Key Laboratory of High-Temperature Structural Materials & Coatings Technology (Ministry of Industry and Information Technology), Beihang University, Beihang University6. Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology7. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University8. Department of Materials Science and Engineering, The University of Tennessee9. School of Material Science and Engineering, Lanzhou University of Technology

摘 要：Recently,the eutectic high-entropy alloy（EHEA）,AlCoCrFeNi_2.1,can reach a good balance of strength and ductility.The dual-phase alloy exhibits a eutectic lamellar microstructure with large numbers of interfaces.However,the role of the interfaces in plastic deformation have not been revealed deeply.In the present work,the orientation relationship（OR） of the interfaces has been clarified as the Kurdjumov-Sachs（KS） interfaces pre senting■ independent of their morphologies.There exist three kinds of interfaces in the EHEA,namely,■.The dominating■ interface and the secondary ■interface are both non-slip planes and atomistic-scale faceted,facilitating the nucleation and slip transmission of the dislocations.The formation mechanism of the preferred interfaces is revealed using the atomistic geometrical analysis according to the criteria of the low interfacial energy based on the coincidence-site lattice（CSL） theory.In particular,the ductility of the dual-phase alloy originates from the KS interface-induced slip continuity across interfaces,which provides a high slip-transfer geometric factor.Moreover,the strengthening effect can be attributed to the interface resistance for the dislocation transmission due to the mismatches of the moduli and lattice parameters at the interfaces.

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