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

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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Microstructure and Mechanical Properties of Ti–Al–Ni–Cr–Co–Fe-Based High-Entropy Alloys

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-019-01708-x ◽

2019 ◽

Vol 72 (6) ◽

pp. 1413-1416

Author(s):

R. Anand Sekhar ◽

Srinivasa Rao Bakshi

Keyword(s):

Mechanical Properties ◽

High Entropy Alloys ◽

High Entropy ◽

Microstructure And Mechanical Properties

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Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys

Intermetallics ◽

10.1016/j.intermet.2011.01.004 ◽

2011 ◽

Vol 19 (5) ◽

pp. 698-706 ◽

Cited By ~ 902

Author(s):

O.N. Senkov ◽

G.B. Wilks ◽

J.M. Scott ◽

D.B. Miracle

Keyword(s):

Mechanical Properties ◽

High Entropy Alloys ◽

High Entropy

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Microstructure and Mechanical Properties of VTaTiMoAlx Refractory High Entropy Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.638 ◽

2017 ◽

Vol 898 ◽

pp. 638-642 ◽

Cited By ~ 7

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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