scholarly journals Effect of Annealing on Microstructure and Mechanical Properties of Al0.5CoCrFeMoxNi High-Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 812 ◽  
Author(s):  
Yan-Xin Zhuang ◽  
Xiu-Lan Zhang ◽  
Xian-Yu Gu
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
High Entropy Alloys ◽  
Obvious Effect ◽  
Σ Phase ◽  
High Entropy ◽  
Phase Constituent ◽  
Microstructure And Mechanical Properties ◽  
Bcc Phase ◽  
Good Agreement

The effect of annealing temperature on the microstructure, phase constituents and mechanical properties of Al0.5CoCrFeMoxNi high-entropy complex alloys has been investigated at a fixed annealing time (10 h). The 600 °C-annealing has no obvious effect on their microstructures, while the annealing at 800–1200 °C enhances the precipitation of (Al,Ni)-rich ordered BCC phase or/and (Cr,Mo)-rich σ phase, and thereby greatly affects the microstructure and mechanical properties of the alloys. All the annealed Al0.5CoCrFeNi alloys are composed of FCC and (Al,Ni)-rich ordered BCC phases; the phase constituent of the Al0.5CoCrFeMo0.1Ni alloy changes from FCC + BCC (600 °C) to FCC + BCC + σ (800 °C) and then to FCC + BCC (1100 °C); the phase constituents of the Al0.5CoCrFeMo0.2Ni and Al0.5CoCrFeMo0.3Ni alloys change from FCC + BCC + σ to FCC + BCC with the annealing temperature rising from 600 to 1200 °C; while all the annealed Al0.5CoCrFeMo0.4Ni and Al0.5CoCrFeMo0.5Ni alloys consist of FCC, BCC and σ phases. The phase constituents of most of the alloys investigated are in good agreement with the calculated results from Thermo-Calc program. The alloys annealed at 800 °C under current investigation conditionshave relative fine precipitations and microstructure, and thereby higher hardness and yield stress.

scholarly journals Effects of the Replacement of Co with Ni on the Microstructure, Mechanical Properties, and Age Hardening of AlCo1−xCrFeNi1+x High-Entropy Alloys

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2665
Author(s):  
Che-Fu Lee ◽  
Tao-Tsung Shun
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Dendritic Structure ◽  
Age Hardening ◽  
Molar Ratio ◽  
High Entropy Alloys ◽  
Σ Phase ◽  
High Entropy ◽  
Fcc Phase ◽  
Bcc Phase

In this study, effects of the replacement of Co with Ni on the microstructure, mechanical properties, and age hardening of high-entropy alloys of AlCo1−xCrFeNi1+x (x = molar ratio; x = 0, 0.5, 1, denoted as X0, X0.5, and X1, respectively) were investigated. These three alloys exhibited a dendritic structure comprising an ordered BCC matrix, a BCC phase, and an FCC or an ordered FCC phase. From X0 to X1 alloys, the yield stress and compressive stress decreased from 1202 and 1790 MPa to 693 and 1537 MPa, respectively. However, fracture strain increased from 0.15 to 0.42. Peak age hardening at 600 °C for the X0 alloy was due to the precipitation of the (Cr,Fe)-rich σ phase. Peak age hardening for the X0.5 and X1 alloys was observed at 500 °C because of the precipitation of the σ phase and BCC phase, respectively.

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.

Microstructure and Mechanical Properties of VTaTiMoAlx Refractory High Entropy Alloys

2017 ◽  
Vol 898 ◽  
pp. 638-642 ◽  
Author(s):  
Dong Xu Qiao ◽  
Hui Jiang ◽  
Xiao Xue Chang ◽  
Yi Ping Lu ◽  
Ting Ju Li
Keyword(s):  
Mechanical Properties ◽  
Vacuum Arc ◽  
High Entropy Alloys ◽  
X Ray Diffraction ◽  
Dendrite Structure ◽  
X Ray ◽  
High Entropy ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Microstructure And Mechanical Properties

A series of refractory high-entropy alloys VTaTiMoAlx with x=0,0.2,0.6,1.0 were designed and produced by vacuum arc melting. The effect of added Al elements on the microstructure and mechanical properties of refractory high-entropy alloys were investigated. The X-ray diffraction results showed that all the high-entropy alloys consist of simple BCC solid solution. SEM indicated that the microstructure of VTaTiMoAlx changes from equiaxial dendritic-like structure to typical dendrite structure with the addition of Al element. The composition of different regions in the alloys are obtained by energy dispersive spectroscopy and shows that Ta, Mo elements are enriched in the dendrite areas, and Al, Ti, V are enriched in inter-dendrite areas. The yield strength and compress strain reach maximum (σ0.2=1221MPa, ε=9.91%) at x=0, and decrease with the addition of Al element at room temperature. Vickers hardness of the alloys improves as the Al addition.

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