“High-entropy polymers”: A new route of polymer mixing with suppressed phase separation

Phase separation phenomena in high-entropy alloys (HEAs) have attracted much attention since their discovery, but little attention has been given to the dynamics of the deformation mechanism of this kind of HEA during uniaxial tension, which limits their widespread and practical utility. In this work, molecular dynamics simulation was used to study the effect of phase separation on the mechanical properties of an HEA under uniaxial tensile loading. Moreover, the associated deformation behavior of the Co–Cr–Cu–Fe–Ni HEA was investigated at the nanoscale. Models with Cu-rich grain boundaries or grains were constructed. The results showed that Cu-rich grain boundaries or grains lowered the strength of the Co–Cr–Cu–Fe–Ni HEA, and Cu-rich grain boundaries significantly reduced ductility. This change of mechanical properties was closely associated with a deformation behavior. Furthermore, the deformation behavior was affected by the critical resolved shear stress of Cu-rich and Cu-depleted regions and the uneven stress distribution caused by phase separation. In addition, dislocation slipping and grain boundary sliding were the main mechanisms of plastic deformation in the Co–Cr–Cu–Fe–Ni HEA.

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Nano-phase formation accompanying phase separation in undercooled CoCrCuFeNi-3 at.% Sn high entropy alloy

Materials Characterization ◽

10.1016/j.matchar.2018.08.008 ◽

2018 ◽

Vol 144 ◽

pp. 516-521 ◽

Cited By ~ 11

Author(s):

S. Wang ◽

Z. Chen ◽

L.C. Feng ◽

Y.Y. Liu ◽

P. Zhang ◽

...

Keyword(s):

Phase Separation ◽

Phase Formation ◽

High Entropy Alloy ◽

High Entropy

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Liquid Phase Separation in Ag-Co-Cr-Fe-Mn-Ni, Co Cr-Cu-Fe-Mn-Ni and Co-Cr-Cu-Fe-Mn-Ni-B High Entropy Alloys for Biomedical Application

Crystals ◽

10.3390/cryst10060527 ◽

2020 ◽

Vol 10 (6) ◽

pp. 527 ◽

Cited By ~ 1

Author(s):

Takeshi Nagase ◽

Mitsuharu Todai ◽

Takayoshi Nakano

Keyword(s):

Phase Separation ◽

Liquid Phase ◽

Biomedical Application ◽

Melting Process ◽

Liquid Phase Separation ◽

Heat Of Mixing ◽

High Entropy Alloys ◽

High Entropy ◽

Metallic Biomaterials ◽

Fundamental Research

The liquid phase separation (LPS) behavior in Co-Cr-based high-entropy alloys (HEAs) is an important target for the development of Co-Cr-based HEAs for metallic biomaterials (BioHEAs). The solidification microstructure in Ag-Co-Cr-Fe-Mn-Ni-Ag, Co-Cr-Cu-Fe-Mn-Ni-Cu, and Co-Cr-Cu-Fe-Mn-Ni-B HEAs, which were designed as the combination of the equiatomic CoCrFeMnNi with Ag, Cu, and the interstitial element of B, was investigated as the fundamental research of LPS in Co-Cr-based HEAs. Ingots of equiatomic AgCoCrFeMnNi, equiatomic CoCrCuFeMnNi, non-equiatomic CoCrCuxFeMnNi (x = 2, 3), and CoCrCuxFeMnNiB0.2 (x = 1, 2, 3) with a small amount of B were fabricated using the arc-melting process. A macroscopic phase-separated structure was observed in the ingots of the equiatomic AgCoCrFeMnNi and CoCrCuxFeMnNiB0.2 (x = 2, 3) HEAs. The addition of a small amount of B enhanced the LPS tendency in the Co-Cr-Fe-Mn-Ni-Cu HEAs. The LPS behavior was discussed through the heat of mixing and computer coupling of phase diagrams and thermochemistry (CALPHAD).

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