Multiscale hierarchical heterostructure yields combined high strength and excellent ductility in a Co-Cr-Fe-Ni-Al negative enthalpy alloy

An，Zibing1,2; Mao，Shengcheng1; Vayyala，Ashok3,4; Yang，Luyan1,3; Jiang，Cheng1; Shi，Caijuan5; Liu，Yi6; Zhou，Hao6; Liao，Xiaozhou7; Zhang，Ze1,8; Han，Xiaodong1,2

2024-12-01

10.1016/j.actamat.2024.120366

Acta Materialia   影响因子和分区

1359-6454

Developing high-performance metallic materials with high yield strength and excellent ductility is important for various applications, such as automobiles, power plants, and aerospace industries. However, conventional alloys typically exhibit a trade-off between strength and ductility, making it difficult to develop materials that are both strong and ductile. In this study, we report that a cast Co-Cr-Fe-Ni-Al alloy can achieve a high room temperature yield strength of up to 500 MPa, which is twice that of conventional high-entropy alloys (HEAs) with face-centered cubic structures, with a tensile strain of 29 %. After thermomechanical treatment, the alloy exhibits even better synergy of strength and ductility, with a yield strength of 900 MPa and 30 % elongation. These exceptional mechanical properties are conferred by a multiscale hierarchical heterostructure, which was introduced through careful control of the alloy composition using a negative enthalpy alloy design strategy. The heterostructure ranges from the micrometer to sub-micrometer and nanometer scales. This multiscale hierarchical structure acts as a continuous impediment to dislocation motion, greatly increasing strength, and facilitating hetero-deformation induced hardening via strain partitioning, resulting in sustained ultrahigh strain hardening. Importantly, multiscale hierarchical heterostructures facilitate coordinated plastic deformation and multiple plastic deformation mechanisms, and stress concentration relieving, and play important roles in improving ductility. This work reveals the effect of different types (and scales) of heterogeneities on the deformation mechanism of HEAs and opens new perspectives for constructing heterostructures, which serve as a new design approach for high strength and excellent ductility by using a negative enthalpy alloy design strategy.

Dislocation Multiscale hierarchical heterostructure Negative enthalpy alloy Strain hardening Strength and ductility

英语

其他

2-s2.0-85203256697

Scopus

1.Beijing Key Laboratory of Microstructure and Property of Advanced Materials,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing,100124,China
2.Department of Materials Science & Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons,Forschungszentrum Jülich GmbH,Jülich,52425,Germany
4.Central Facility for Electron Microscopy (GFE),RWTH Aachen University,Aachen,Ahornstr. 55,52074,Germany
5.Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,100049,China
6.Nano and Heterogeneous Structural Materials Center,School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing,210094,China
7.School of Aerospace,Mechanical and Mechatronic Engineering,The University of Sydney,Sydney,Australia
8.State Key Laboratory of Silicon Materials,Department of Materials Science and Engineering,Zhejiang University,Hangzhou,310058,China

An，Zibing,Mao，Shengcheng,Vayyala，Ashok,et al. Multiscale hierarchical heterostructure yields combined high strength and excellent ductility in a Co-Cr-Fe-Ni-Al negative enthalpy alloy[J]. Acta Materialia,2024,281.

An，Zibing.,Mao，Shengcheng.,Vayyala，Ashok.,Yang，Luyan.,Jiang，Cheng.,...&Han，Xiaodong.(2024).Multiscale hierarchical heterostructure yields combined high strength and excellent ductility in a Co-Cr-Fe-Ni-Al negative enthalpy alloy.Acta Materialia,281.

An，Zibing,et al."Multiscale hierarchical heterostructure yields combined high strength and excellent ductility in a Co-Cr-Fe-Ni-Al negative enthalpy alloy".Acta Materialia 281(2024).