A New High‐Entropy Alloy of Al–Fe–Co–Ni–Cu Possessing Single Face‐Centered Cubic Crystal Structure and Excellent Mechanical Properties at Room Temperature

2021 ◽  
pp. 2000825
Author(s):  
Sujit Das ◽  
Saurabh Kumar Nishad ◽  
P.S Robi
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Room Temperature ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Cubic Crystal ◽  
High Entropy ◽  
Single Face ◽  
Face Centered

Study on Corrosion Resistance of High-Entropy Alloys NiCoCrFeMnCuC in Medium Acid Liquid

2011 ◽  
Vol 117-119 ◽  
pp. 1816-1819 ◽  
Author(s):  
Ze Liu ◽  
Jian Min Zeng ◽  
Hai Hong Zhan
Keyword(s):  
Crystal Structure ◽  
Corrosion Resistance ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Arc Furnace ◽  
Cubic Crystal ◽  
High Entropy ◽  
Excellent Corrosion Resistance ◽  
Face Centered ◽  
Loss Experiment

High-entropy alloy of NiCoCrFeMnCuC were made by vacuum non-consumable arc furnace in the present work. The crystal structure of NiCoCrFeMnCuC was analyzed by XRD. The corrosion resistance of NiCoCrFeMnCuC in 10%HNO3-3%HF, 10%H2SO4, 5%HCl and 10%HF was investigated, respectively with weight loss experiment. The results show that main intermetallics of the alloy are CoCx, FeNi3 and Fe3Mn7. The NiCoCrFeMnCuC has simple crystal structures with face-centered cubic crystal structure FCC and Quartet and has excellent corrosion resistance in some medium acid liquids.

scholarly journals Effect of Mn Addition on the Microstructures and Mechanical Properties of CoCrFeNiPd High Entropy Alloy

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 288
Author(s):  
Yiming Tan ◽  
Jinshan Li ◽  
Jun Wang ◽  
Hongchao Kou
Keyword(s):  
Intermetallic Compound ◽  
Interface Energy ◽  
High Entropy Alloy ◽  
Strengthening Effect ◽  
Face Centered Cubic ◽  
Liquid Interfaces ◽  
High Entropy ◽  
Single Face ◽  
Face Centered ◽  
Fcc Phase

CoCrFeNiPdMnx (x = 0, 0.2, 0.4, 0.6, 0.8) high entropy alloys (HEAs) were prepared and characterized. With an increase in Mn addition, the microstructures changed from dendrites (CoCrFeNiPd with a single face-centered-cubic (FCC) phase) to divorced eutectics (CoCrFeNiPdMn0.2 and CoCrFeNiPdMn0.4), to hypoeutectic microstructures (CoCrFeNiPdMn0.6), and finally to seaweed eutectic dendrites (CoCrFeNiPdMn0.8). The addition of Mn might change the interface energy anisotropy of both the FCC/liquid and MnPd-rich intermetallic compound/liquid interfaces, thus forming the seaweed eutectic dendrites. The hardness of the FCC phase was found to be highly related to the solute strengthening effect, the formation of nanotwins and the transition from CoCrFeNiPd-rich to CoCrFeNi-rich FCC phase. Hierarchical nanotwins were found in the MnPd-rich intermetallic compound and a decrease in either the spacing of primary twins or secondary twins led to an increase in hardness. The designing rules of EHEAs were discussed and the pseudo binary method was revised accordingly.

Characterization of Co-Cr-Mo Alloys Used in HIP Implant Articulating Surfaces

1996 ◽  
Vol 441 ◽  
Author(s):  
R. Varano ◽  
J. D. Bobyn ◽  
S. Yue
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Boundary ◽  
Room Temperature ◽  
Volume Fraction ◽  
Face Centered Cubic ◽  
Hip Implant ◽  
Fine Microstructure ◽  
Face Centered

AbstractThe microstructure, crystallography and mechanical properties of a wrought (ASTM F-1537) Co-Cr- Mo hip implant alloy were studied in this work. The effects of carbon content, heat treatment and room temperature compression on the above characteristics were also analyzed. Metallography of the asreceived material revealed the presence of ‘twins’ in a relatively fine microstructure with some randomly distributed grain boundary carbides. Heat treatment of the specimens produced a coarser microstructure, more uniformly distributed grain boundary carbides and annealing twins. Neutron diffraction of the specimens, which were deformed at room temperature, exhibited an increase in the volume fraction of the more stable Co-hexagonal closed-packed (HCP) crystal structure, due to a strain-induced transformation (SIT) from the metastable Co-face-centered cubic (FCC) crystal structure. It was also seen that the higher C specimens, as well as the heat treated specimens, possessed a lower volume fraction of the HCP phase. It was found, through shear punch testing, that the deformed specimens exhibited higher mechanical properties without any significant losses to the ductility of the material.

scholarly journals Microstructure, Texture, and Strength Development during High-Pressure Torsion of CrMnFeCoNi High-Entropy Alloy

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 336 ◽  
Author(s):  
Werner Skrotzki ◽  
Aurimas Pukenas ◽  
Eva Odor ◽  
Bertalan Joni ◽  
Tamas Ungar ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Strength Development ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
X Ray ◽  
High Entropy ◽  
Face Centered

The equiatomic face-centered cubic high-entropy alloy CrMnFeCoNi was severely deformed at room and liquid nitrogen temperature by high-pressure torsion up to shear strains of about 170. Its microstructure was analyzed by X-ray line profile analysis and transmission electron microscopy and its texture by X-ray microdiffraction. Microhardness measurements, after severe plastic deformation, were done at room temperature. It is shown that at a shear strain of about 20, a steady state grain size of 24 nm, and a dislocation density of the order of 1016 m−2 is reached. The dislocations are mainly screw-type with low dipole character. Mechanical twinning at room temperature is replaced by a martensitic phase transformation at 77 K. The texture developed at room temperature is typical for sheared face-centered cubic nanocrystalline metals, but it is extremely weak and becomes almost random after high-pressure torsion at 77 K. The strength of the nanocrystalline material produced by high-pressure torsion at 77 K is lower than that produced at room temperature. The results are discussed in terms of different mechanisms of deformation, including dislocation generation and propagation, twinning, grain boundary sliding, and phase transformation.

scholarly journals A high-entropy alloy with hierarchical nanoprecipitates and ultrahigh strength

2018 ◽  
Vol 4 (10) ◽  
pp. eaat8712 ◽  
Author(s):  
Zhiqiang Fu ◽  
Lin Jiang ◽  
Jenna L. Wardini ◽  
Benjamin E. MacDonald ◽  
Haiming Wen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Failure Strain ◽  
Tensile Yield Strength ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Metallic Materials ◽  
Strengthening Mechanisms ◽  
High Entropy ◽  
Face Centered ◽  
Fcc Phase

High-entropy alloys (HEAs) are a class of metallic materials that have revolutionized alloy design. They are known for their high compressive strengths, often greater than 1 GPa; however, the tensile strengths of most reported HEAs are limited. Here, we report a strategy for the design and fabrication of HEAs that can achieve ultrahigh tensile strengths. The proposed strategy involves the introduction of a high density of hierarchical intragranular nanoprecipitates. To establish the validity of this strategy, we designed and fabricated a bulk Fe25Co25Ni25Al10Ti15 HEA to consist of a principal face-centered cubic (fcc) phase containing hierarchical intragranular nanoprecipitates. Our results show that precipitation strengthening, as one of the main strengthening mechanisms, contributes to a tensile yield strength (σ0.2) of ~1.86 GPa and an ultimate tensile strength of ~2.52 GPa at room temperature, which heretofore represents the highest strength reported for an HEA with an appreciable failure strain of ~5.2%.

scholarly journals Constitutive modeling of deformation behavior of high-entropy alloys with face-centered cubic crystal structure

2017 ◽  
Vol 5 (5) ◽  
pp. 350-356 ◽  
Author(s):  
Min Ji Jang ◽  
Dong-Hyun Ahn ◽  
Jongun Moon ◽  
Jae Wung Bae ◽  
Dami Yim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Constitutive Modeling ◽  
Deformation Behavior ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
Cubic Crystal ◽  
High Entropy ◽  
Face Centered

Strengthening of a CoCrFeNiMn-Type High Entropy Alloy by Regular Arrays of Nanoprecipitates

2018 ◽  
Vol 941 ◽  
pp. 772-777 ◽  
Author(s):  
Nikita Stepanov ◽  
Dmitry Shaysultanov ◽  
Margarita Klimova ◽  
Vladimir Sanin ◽  
Sergey Zherebtsov
Keyword(s):  
Cold Rolling ◽  
Coarse Grained ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Single Face ◽  
Cold Rolling And Annealing ◽  
M23c6 Type ◽  
Face Centered ◽  
Fcc Phase

In this paper, we report microstructure and mechanical properties evolution of the CoCrFeNiMn-type high entropy alloy, containing small amounts of Al and C, during cold rolling and subsequent annealing at 700-1100°C. In the initial as-cast condition the alloy has coarse-grained single face-centered cubic (fcc) phase structure. Cold rolling and annealing substantially refine fcc grains; in addition M23C6 type carbides appear. After annealing at relatively low temperatures (≤900°C), these particles are arranged in characteristic arrays aligned with rolling directions. The specific microstructure of the thermomechanically processed alloy is suggested to be the reason of the balanced combination of tensile strength and ductility.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
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.

scholarly journals Development of Novel Lightweight Al-Rich Quinary Medium-Entropy Alloys with High Strength and Ductility

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4223
Author(s):  
Po-Sung Chen ◽  
Yu-Chin Liao ◽  
Yen-Ting Lin ◽  
Pei-Hua Tsai ◽  
Jason S. C. Jang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compressive Strain ◽  
High Strength ◽  
Fine Tuning ◽  
Face Centered Cubic ◽  
Transportation Industry ◽  
High Entropy ◽  
Good Potential ◽  
Face Centered

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50–Ti–Cr–Mn–V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.

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