Simultaneously enhancing the ultimate strength and ductility of high-entropy alloys via short-range ordering

AbstractSimultaneously enhancing strength and ductility of metals and alloys has been a tremendous challenge. Here, we investigate a CoCuFeNiPd high-entropy alloy (HEA), using a combination of Monte Carlo method, molecular dynamic simulation, and density-functional theory calculation. Our results show that this HEA is energetically favorable to undergo short-range ordering (SRO), and the SRO leads to a pseudo-composite microstructure, which surprisingly enhances both the ultimate strength and ductility. The SRO-induced composite microstructure consists of three categories of clusters: face-center-cubic-preferred (FCCP) clusters, indifferent clusters, and body-center-cubic-preferred (BCCP) clusters, with the indifferent clusters playing the role of the matrix, the FCCP clusters serving as hard fillers to enhance the strength, while the BCCP clusters acting as soft fillers to increase the ductility. Our work highlights the importance of SRO in influencing the mechanical properties of HEAs and presents a fascinating route for designing HEAs to achieve superior mechanical properties.

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Short-range ordering induced serrated flow in a carbon contained FeCoCrNiMn high entropy alloy

Micron ◽

10.1016/j.micron.2019.102739 ◽

2019 ◽

Vol 126 ◽

pp. 102739 ◽

Cited By ~ 3

Author(s):

Lin Guo ◽

Ji Gu ◽

Xing Gong ◽

Kai Li ◽

Song Ni ◽

...

Keyword(s):

Short Range ◽

High Entropy Alloy ◽

Serrated Flow ◽

High Entropy ◽

Short Range Ordering

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Short-range ordering and its effects on mechanical properties of high-entropy alloys

Journal of Material Science and Technology ◽

10.1016/j.jmst.2020.06.018 ◽

2021 ◽

Vol 62 ◽

pp. 214-220 ◽

Cited By ~ 4

Author(s):

Yuan Wu ◽

Fei Zhang ◽

Xiaoyuan Yuan ◽

Hailong Huang ◽

Xiaocan Wen ◽

...

Keyword(s):

Mechanical Properties ◽

Short Range ◽

High Entropy Alloys ◽

High Entropy ◽

Short Range Ordering

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A critical review of the mechanical properties of CoCrNi-based medium-entropy alloys

Microstructures ◽

10.20517/microstructures.2021.10 ◽

2022 ◽

Author(s):

Dingfeng Xu ◽

Mingliang Wang ◽

Tianxin Li ◽

Xiangsai Wei ◽

Yiping Lu

Keyword(s):

Mechanical Properties ◽

First Generation ◽

Mechanical Performance ◽

Chemical Compositions ◽

High Entropy ◽

Tensile Response ◽

Short Range Ordering ◽

Critical Resolved Shear Stress ◽

Development Prospects ◽

Strength And Ductility

The CoCrFeMnNi alloy is one of the most notable first-generation high-entropy alloys and is also known as a Cantor alloy. This alloy was first proposed in 2004 and shows promising performance at cryogenic temperatures (CTs). Subsequent research has indicated that the equiatomic ternary CoCrNi medium-entropy alloy (MEA), as a subset of the Cantor alloy family, has better mechanical properties than the CoCrFeMnNi alloy. Interestingly, both the strength and ductility of the CoCrNi MEA are higher at CTs than at room temperature. CoCrNi-based alloys have attracted considerable attention in the metallic materials community and it is therefore important to generalize and summarize the latest progress in CoCrNi-based MEA research. The present review initially briefly introduces the discovery of the CoCrNi MEA. Subsequently, its tensile response and deformation mechanisms are summarized. In particular, the effects of parameters, such as critical resolved shear stress, stacking fault energy and short-range ordering, on the deformation behavior are discussed in detail. The methods for strengthening the CoCrNi MEA are then reviewed and divided into two categories, namely, modifying microstructures and adjusting chemical compositions. In addition, the mechanical performance of CoCrNi-based MEAs, including their dynamic shear properties, creep behavior and fracture toughness, is also deliberated. Finally, the development prospects of CoCrNi-based MEAs are proposed.

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Chemical short-range order in derivative Cr–Ta–Ti–V–W high entropy alloys from the first-principles thermodynamic study

Physical Chemistry Chemical Physics ◽

10.1039/d0cp03764h ◽

2020 ◽

Vol 22 (41) ◽

pp. 23929-23951

Author(s):

Damian Sobieraj ◽

Jan S. Wróbel ◽

Tomasz Rygier ◽

Krzysztof J. Kurzydłowski ◽

Osman El Atwani ◽

...

Keyword(s):

Density Functional Theory ◽

Monte Carlo ◽

First Principles ◽

Short Range ◽

Density Functional ◽

Short Range Order ◽

High Entropy Alloys ◽

Functional Theory ◽

High Entropy ◽

Short Range Ordering

Density Functional Theory (DFT), Cluster Expansion and Monte Carlo simulations have been carried out to investigate the short-range ordering in high-entropy alloys in Cr–Ta–Ti–V–W system as a function of temperature and composition.

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Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽

10.3390/met9030345 ◽

2019 ◽

Vol 9 (3) ◽

pp. 345 ◽

Cited By ~ 3

Author(s):

Lianzan Yang ◽

Yongyan Li ◽

Zhifeng Wang ◽

Weimin Zhao ◽

Chunling Qin

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

High Specific Surface Area ◽

High Entropy Alloy ◽

Face Centered Cubic ◽

High Entropy ◽

Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

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Effects of microstructure and temperature on the mechanical properties of nanocrystalline CoCrFeMnNi high entropy alloy under nanoscratching using molecular dynamics simulation

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.159516 ◽

2021 ◽

Vol 871 ◽

pp. 159516

Author(s):

Yuming Qi ◽

Tengwu He ◽

Heming Xu ◽

Yandong Hu ◽

Miao Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Dynamics Simulation ◽

High Entropy Alloy ◽

High Entropy

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The effect of Cu and Mn elements on the mechanical properties of single-crystal CoCrFeNi-based high-entropy alloy under nanoindentation

Journal of Applied Physics ◽

10.1063/5.0043034 ◽

2021 ◽

Vol 129 (19) ◽

pp. 195104

Author(s):

Yuming Qi ◽

Tengwu He ◽

Miaolin Feng

Keyword(s):

Mechanical Properties ◽

Single Crystal ◽

High Entropy Alloy ◽

High Entropy

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Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Coatings ◽

10.3390/coatings11010041 ◽

2021 ◽

Vol 11 (1) ◽

pp. 41

Author(s):

Yin-Yu Chang ◽

Cheng-Hsi Chung

Keyword(s):

Mechanical Properties ◽

Nitrogen Content ◽

Adhesion Strength ◽

Mechanical Performance ◽

Bulk Material ◽

High Entropy Alloy ◽

Composition Gradient ◽

Multilayered Structures ◽

High Entropy ◽

Alloy Target

Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.

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