scholarly journals Microstructures and Mechanical Properties of Al-Ti-Zr-Nb-Ta-Mo-V Refractory High-Entropy Alloys with Coherent B2 Nanoprecipitation

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 833
Author(s):  
Zhenhua Wang ◽  
Dongming Jin ◽  
Jincan Han ◽  
Qing Wang ◽  
Zhongwei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lattice Misfit ◽  
Particle Morphology ◽  
High Yield ◽  
High Entropy Alloys ◽  
High Yield Strength ◽  
High Entropy ◽  
B2 Phase ◽  
The Difference ◽  
Compressive Mechanical Property

In this work, the microstructural evolution and mechanical properties of new body-centered cubic (BCC)-based Al-Ti-Zr-Nb-Ta-Mo-V refractory high-entropy alloys (RHEAs) with coherent B2 precipitation are investigated. These designed alloy ingots were solid-solutionized at 1573 K for 2 h and then aged at 873 K for 24 h, in which each treatment was followed by water quenching. It was found that there exists phase separation of BCC matrix, Ti/Zr-rich BCC1 and Nb/Ta-rich BCC2 in these alloys. Moreover, ultra-fine spherical B2 nanoparticles with a size of 3~5 nm were dispersed in BCC2 matrix. These B2 nanoparticles could be coarsened up to 25~50 nm after aging and the particle morphology also changes to a cuboidal shape due to a moderate lattice misfit (ε = 0.7~2.0%). Also, Zr5Al3 phase could coexist with the B2 phase, where the difference between them is that the Ti element is enriched in B2 phase, rather than in Zr5Al3. Among them, the solutionized Al2Ti5Zr4Nb2.5Ta2.5 RHEAs exhibit good compressive mechanical property with a high yield strength of 1240 MPa and a large plasticity, which is mainly attributed to the coherent precipitation in the BCC matrix.

scholarly journals The effect of cooling rate on structure and mechanical properties of Co-Cr-Cu-Fe-Ni-Sn high entropy alloys

2021 ◽  
Vol 29 (1) ◽  
pp. 85-90
Author(s):  
O. I. Kushnerov ◽  
V. F. Bashev
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Enthalpy Of Mixing ◽  
High Entropy Alloys ◽  
Alloy Structure ◽  
Simultaneous Formation ◽  
High Entropy ◽  
Splat Quenching ◽  
The Difference ◽  
Atomic Radii

The paper examines the structure and mechanical properties of multicomponent high-entropy CoCrCuFeNiSnx alloys in as-cast and splat-quenched states. The compositions of investigated alloys is analyzed by using the criteria for predicting the phase composition of high-entropy alloys available in the literature, based both on calculations of the entropy and enthalpy of mixing and on an estimate of the difference between the atomic radii of the component. The alloy films is fabricated by the known technique of splat-quenching. A cooling rate estimated by a film thickness is ~ 106 K/s. The simultaneous formation of two solid solutions (FCC + ordered BCC) has been established in the alloy structure. An increase in the concentration of Sn favors the formation of the ordered (В2 type) solid solution in the structure of the alloys. High values of the microhardness and dislocation density have been obtained in the splat-quenched samples. It is also shown that an increase in the Sn content positively affects the microhardness.

Effect of the structure of vacuum condensates of high entropy alloys of Cr–Fe–Co–Ni–Cu system on their mechanical properties

2020 ◽  
Vol 2020 (4) ◽  
pp. 16-22
Author(s):  
A.I. Ustinov ◽  
◽  
V.S. Skorodzievskii ◽  
S.A. Demchenkov ◽  
S.S. Polishchuk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Vacuum Condensates

Powder plasma arc additive manufactured CoCrFeNi(SiC)x high-entropy alloys: Microstructure and mechanical properties

2021 ◽  
Vol 282 ◽  
pp. 128736 ◽  
Author(s):  
Qingkai Shen ◽  
Xiangdong Kong ◽  
Xizhang Chen ◽  
Xukai Yao ◽  
Vladislav B. Deev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Entropy Alloys ◽  
Plasma Arc ◽  
High Entropy ◽  
Microstructure And Mechanical Properties

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

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.

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

JOM ◽  
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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