Synthesis and Characterization of Novel High Entropy Alloys

High entropy alloys (HEAs) generally exhibit either high resistance to deformation or high toughness due to the presence of body-centered or face-centered cubic structure, respectively. To overcome these limitations, new high entropy alloys have been developed in the present study. This investigation aims to synthesis and characterization of novel CoCrFeNi3Si, CoCrFe2Ni2Si, and Co2CrFeNi2Si high entropy alloys. The mechanical alloying route is used to synthesize these alloys. Grinding was carried out to 20h and X-ray diffraction (XRD) analysis was done at different time intervals of grinding. The face-centered cubic structure along with the intermetallic compound of Ni-Si was observed after 20h of grinding. Furthermore, a pseudo binary strategy based on the valence electron concentration and mixing enthalpy is also employed to design the high entropy alloys considered in the present study. Carefully analysis of the XRD pattern indicates that from 5 to 20h of mechanical alloying there is a decrement in the initial peaks of elements observed.

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Synthesis and Characterization of Ru Cubic Nanocages with a Face-Centered Cubic Structure by Templating with Pd Nanocubes

Nano Letters ◽

10.1021/acs.nanolett.6b02795 ◽

2016 ◽

Vol 16 (8) ◽

pp. 5310-5317 ◽

Cited By ~ 67

Author(s):

Ming Zhao ◽

Legna Figueroa-Cosme ◽

Ahmed O. Elnabawy ◽

Madeline Vara ◽

Xuan Yang ◽

...

Keyword(s):

Synthesis And Characterization ◽

Face Centered Cubic ◽

Cubic Structure ◽

Face Centered

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Prediction of Face-Centered Cubic Single-Phase Formation for Non-Equiatomic Cr–Mn–Fe–Co–Ni High-Entropy Alloys Using Valence Electron Concentration and Mean-Square Atomic Displacement

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.mt-m2020144 ◽

2020 ◽

Vol 61 (9) ◽

pp. 1874-1880

Author(s):

Kodai Niitsu ◽

Makoto Asakura ◽

Koretaka Yuge ◽

Haruyuki Inui

Keyword(s):

Valence Electron ◽

Single Phase ◽

Atomic Displacement ◽

Valence Electron Concentration ◽

High Entropy Alloys ◽

Face Centered Cubic ◽

Mean Square ◽

High Entropy ◽

Face Centered ◽

Single Phase Formation

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Effects of Different Contents of Each Component on the Structural Stability and Mechanical Properties of Co-Cr-Fe-Ni High-Entropy Alloys

Applied Sciences ◽

10.3390/app11062832 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2832

Author(s):

Haibo Liu ◽

Cunlin Xin ◽

Lei Liu ◽

Chunqiang Zhuang

Keyword(s):

Mechanical Properties ◽

Structural Stability ◽

High Entropy Alloys ◽

Face Centered Cubic ◽

Obvious Effect ◽

High Entropy ◽

Precise Control ◽

Component Content ◽

Face Centered ◽

And Performance

The structural stability of high-entropy alloys (HEAs) is closely related to their mechanical properties. The precise control of the component content is a key step toward understanding their structural stability and further determining their mechanical properties. In this study, first-principle calculations were performed to investigate the effects of different contents of each component on the structural stability and mechanical properties of Co-Cr-Fe-Ni HEAs based on the supercell model. Co-Cr-Fe-Ni HEAs were constructed based on a single face-centered cubic (FCC) solid solution. Elemental components have a clear effect on their structure and performance; the Cr and Fe elements have an obvious effect on the structural stability and equilibrium lattice constant, respectively. The Ni elements have an obvious effect on stiffness. The Pugh ratios indicate that Cr and Ni addition may increase ductility, whereas Co and Fe addition may decrease it. With increasing Co and Fe contents or decreasing Cr and Ni contents, the structural stability and stiffness of Co-Cr-Fe-Ni HEAs are improved. The structural stability and mechanical properties may be related to the strength of the metallic bonding and covalent bonding inside Co-Cr-Fe-Ni HEAs, which, in turn, is determined by the change in element content. Our results provide the underlying insights needed to guide the optimization of Co-Cr-Fe-Ni HEAs with excellent mechanical properties.

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Insights into Defect-Mediated Nucleation of Equilibrium B2 Phase in Face-Centered Cubic High-Entropy Alloys

JOM ◽

10.1007/s11837-021-04754-3 ◽

2021 ◽

Author(s):

Abhishek Sharma ◽

Bharat Gwalani ◽

Sriswaroop Dasari ◽

Deep Choudhuri ◽

Yao-Jen Chang ◽

...

Keyword(s):

High Entropy Alloys ◽

Face Centered Cubic ◽

High Entropy ◽

B2 Phase ◽

Face Centered

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Compositional Dependence of Phase Selection in CoCrCu0.1FeMoNi-Based High-Entropy Alloys

Materials ◽

10.3390/ma11081290 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1290 ◽

Cited By ~ 16

Author(s):

Ning Liu ◽

Chen Chen ◽

Isaac Chang ◽

Pengjie Zhou ◽

Xiaojing Wang

Keyword(s):

Molar Ratio ◽

Mixing Enthalpy ◽

High Entropy Alloy ◽

Valence Electron Concentration ◽

Face Centered Cubic ◽

Distortion Parameter ◽

Local Lattice Distortion ◽

Phase Selection ◽

High Entropy ◽

Fcc Structure

To study the effect of alloy composition on phase selection in the CoCrCu0.1FeMoNi high-entropy alloy (HEA), Mo was partially replaced by Co, Cr, Fe, and Ni. The microstructures and phase selection behaviors of the CoCrCu0.1FeMoNi HEA system were investigated. Dendritic, inter-dendritic, and eutectic microstructures were observed in the as-solidified HEAs. A simple face centered cubic (FCC) single-phase solid solution was obtained when the molar ratio of Fe, Co, and Ni was increased to 1.7 at the expense of Mo, indicating that Fe, Co, and Ni stabilized the FCC structure. The FCC structure was favored at the atomic radius ratio δ ≤ 2.8, valence electron concentration (VEC) ≥ 8.27, mixing entropy ΔS ≤ 13.037, local lattice distortion parameter α2 ≤ 0.0051, and ΔS/δ2 > 1.7. Mixed FCC + body centered cubic (BCC) structures occurred for 4.1 ≤ δ ≤ 4.3 and 7.71 ≤ VEC ≤ 7.86; FCC or/and BCC + intermetallic (IM) mixtures were favored at 2.8 ≤ δ ≤ 4.1 or δ > 4.3 and 7.39 < VEC ≤ 8.27. The IM phase is favored at electronegativity differences greater than 0.133. However, ΔS, α2, and ΔS/δ2 were inefficient in identifying the (FCC or/and BCC + IM)/(FCC + BCC) transition. Moreover, the mixing enthalpy cannot predict phase structures in this system.

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