High strength dual fcc phase CoCuFeMnNi high-entropy alloy wires with dislocation wall boundaries stabilized by phase boundaries

2021 ◽  
pp. 141875
Author(s):  
Sang Hun Shim ◽  
Hesam Pouraliakbar ◽  
Sun Ig Hong
Keyword(s):  
High Strength ◽  
High Entropy Alloy ◽  
Phase Boundaries ◽  
Dislocation Wall ◽  
High Entropy ◽  
Fcc Phase

Diffraction, microstructure and thermal stability analysis in a double phase nanocrystalline Al20Mg20Ni20Cr20Ti20 high entropy alloy

2017 ◽  
Vol 26 (3-4) ◽  
pp. 127-132 ◽  
Author(s):  
A.M. Rameshbabu ◽  
P. Parameswaran ◽  
V. Vijayan ◽  
R. Panneer
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
High Strength ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Plasma Sintering ◽  
Double Phase ◽  
Trial And Error Method ◽  
Superior Corrosion Resistance ◽  
Fcc Phase

AbstractAn effort has been made to develop a new composition of AlMgNiCrTi high entropy alloy (HEA) with a distinct properties includes squat density, intense strength and hardness, superior corrosion resistance, better oxidation resistance, high temperature resistance, fatigue load and crack resistance to congregate the necessity of aircraft applications. The equivalent atomic percentage for the above defined composition is established using analytical correlation for molar and atom renovation by trial and error method. The alloy is synthesized by powder metallurgy technique through mechanical alloying. Succeeding to mechanical alloying it is elucidated that the metal powder is primarily composed of single BCC solid solution with crystallite magnitude <10 nm. It is also observed that the alloy is thermally stable at prominent temperature about 800°C as it is retained its nanostructure which was revealed using differential scanning caloriemetry (DSC). This alloy powder was consolidated and sintered using spark plasma sintering at 800°C with 50 Mpa pressure to a density of 98.83%. Subsequent to sintering, Titanium carbide FCC phase evolved along with the BCC phase. The alloying behavior and phase transformation were studied using X-ray diffraction (XRD) and scanning electron microscope (SEM). The homogeneity of the composition is confirmed by energy dispersive spectroscopy (EDS). The hardness of the alloy is found to be 710±20 HV. The evolutions of the phases and hardness imply that this alloy is apposite for both high strength and high temperature applications.

Solidification Microstructure and Mechanical Properties of Bulk Near-Eutectic AlCoCrFeNi2.2 High Entropy Alloy

2020 ◽  
Vol 993 ◽  
pp. 281-286
Author(s):  
Xuan Huang ◽  
Yao Hu ◽  
Zhang Tong Wu ◽  
Yong Dong ◽  
Chuan Qiang Li ◽  
...  
Keyword(s):  
High Strength ◽  
Eutectic Structure ◽  
High Entropy Alloy ◽  
Induction Melting ◽  
Test Results ◽  
High Entropy ◽  
Compression Performance ◽  
Significant Difference ◽  
Fcc Phase ◽  
Different Parts

A 4Kg grade AlCoCrFeNi2.2 high entropy alloy was prepared by low vacuum medium frequency induction melting. The microstructure results showed that the microstructure and composition of the ingot were uniform. The microstructures were composed of primary Ni-rich FCC phase and eutectic structure. The eutectic structure was composed of Ni-rich FCC phase and Al-rich B2 phase. The hardness results showed no significant difference in Vickers hardness between different parts of the ingot, and fluctuated within the range of HV260 ± 20. The compression test results showed that there was no significant difference in compression performance between different parts of the ingot. The AlCoCrFeNi2.2 high entropy alloy had excellent compression performance, the yield strength reached 600 MPa, the fracture strength reached 2200 MPa, and the compression ratio was greater than 40%. Above all, the near-eutectic AlCoCrFeNi2.2 high-entropy alloy had the characteristics of good casting ability, high strength, good plasticity, and was easy to realize the preparation of large-volume non-segregation ingot.

WReTaMo Refractory High‐Entropy Alloy with High Strength at 1600 °C

2021 ◽  
pp. 2100765
Author(s):  
Yixing Wan ◽  
Qianqian Wang ◽  
Jinyong Mo ◽  
Zhibin Zhang ◽  
Xin Wang ◽  
...  
Keyword(s):  
High Strength ◽  
High Entropy Alloy ◽  
High Entropy

Phase Transition of As-Milled and Annealed CrCuFeMnNi High-Entropy Alloy Powder

NANO ◽  
2018 ◽  
Vol 13 (09) ◽  
pp. 1850100 ◽  
Author(s):  
Rui-Feng Zhao ◽  
Bo Ren ◽  
Guo-Peng Zhang ◽  
Zhong-Xia Liu ◽  
Jian-Jian Zhang
Keyword(s):  
Phase Transition ◽  
Solution Structure ◽  
Milling Time ◽  
Structure Evolution ◽  
High Entropy Alloy ◽  
Chemical Homogeneity ◽  
High Entropy ◽  
Dynamic Phase Transition ◽  
Fcc Phase ◽  
Bcc Phase

The CrCuFeMnNi high entropy alloy (HEA) powder was synthesized by mechanical alloying. The effects of milling time and subsequent annealing on the structure evolution, thermostability and magnetic property were investigated. After 50[Formula: see text]h of milling, the CrCuFeMnNi HEA powder consisted of a major FCC phase and a small amount of BCC phase. The crystallite size and strain lattice of 50[Formula: see text]h-ball-milled CrCuFeMnNi HEA powder were 12[Formula: see text]nm and 1.02%, respectively. The powder exhibited refined morphology and excellent chemical homogeneity. The supersaturated solid solution structure of the as-milled HEA powder transformed into FCC1, FCC2, a small amount of BCC and [Formula: see text] phase in annealed state. Most of the BCC phase decomposed into FCC (mainly FCC2 phase) and [Formula: see text] phases, and the dynamic phase transition was almost in equilibrium at 900[Formula: see text]C. The saturated magnetization and coercivity force of the 50[Formula: see text]h-ball-milled CrCuFeMnNi HEA powder were respectively 16.1[Formula: see text]emu/g and 56.2[Formula: see text]Oe.

scholarly journals On the high temperature coarsening kinetics of γ′ precipitates in a high strength Co37.6Ni35.4Al9.9Mo4.9Cr5.9Ta2.8Ti3.5 fcc-based high entropy alloy

2019 ◽  
Vol 177 ◽  
pp. 82-95 ◽  
Author(s):  
Prafull Pandey ◽  
Sanjay Kashyap ◽  
Dhanalakshmi Palanisamy ◽  
Amit Sharma ◽  
Kamanio Chattopadhyay
Keyword(s):  
High Temperature ◽  
High Strength ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Coarsening Kinetics ◽  
Kinetics Of

Surface hardening of FCC phase high-entropy alloy system by powder-pack boriding

2019 ◽  
Vol 371 ◽  
pp. 389-394 ◽  
Author(s):  
Thomas Lindner ◽  
Martin Löbel ◽  
Benjamin Sattler ◽  
Thomas Lampke
Keyword(s):  
Surface Hardening ◽  
Alloy System ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Fcc Phase

scholarly journals High-Strength Behavior of the Al0.3CoCrFeNi High-Entropy Alloy Single Crystals

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1149
Author(s):  
Irina V. Kireeva ◽  
Yuriy I. Chumlyakov ◽  
Zinaida V. Pobedennaya ◽  
Anna V. Vyrodova ◽  
Anastasia A. Saraeva
Keyword(s):  
Single Crystals ◽  
Yield Point ◽  
Stress Level ◽  
High Stress ◽  
High Strength ◽  
Orientation Dependence ◽  
Temperature Deformation ◽  
High Entropy Alloy ◽  
Shear Stresses ◽  
High Entropy

The main disadvantage of fcc (face-centred cubic lattice) high-entropy alloys is the low stress level at the yield point (σ0.1) at a test temperature above room temperature. This restricts their practical application at high test temperatures from 773 K to 973 K. In this study, we found that a high stress level was reached at the yield point σ0.1 ≈ G/100–G/160 (G is the shear modulus) of the [001]- and [1¯44]-oriented crystals of the Co23.36Cr23.29Fe23.80Ni21.88Al7.67 (Al0.3CoCrFeNi) high-entropy alloy (HEA) within a wide temperature range of 77–973 K under tension, due to the occurrence, of nanotwins, multipoles, dislocations under plastic deformation at 77 K and the subsequent precipitation of ordered L12 and B2 particles. It was shown that grain boundaries are not formed and the samples remain in a single-crystal state after low-temperature deformation and subsequent ageing at 893 K for 50 h. Achieving a high-strength state in the Al0.3CoCrFeNi HEA single crystals induces the orientation dependence of the critical resolved shear stresses (τcr) at T ≥ 200 K (τcr[1¯44] > τcr[001]), which is absent in the initial single-phase crystals, weakens the temperature dependence of σ0.1 above 573 K, and reduces plasticity to 5–13% in the [1¯44] orientation and 15–20% in the [001] orientation.

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.

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