scholarly journals Atomic-scale characterization and modeling of 60° dislocations in a high-entropy alloy

2016 ◽  
Vol 110 ◽  
pp. 352-363 ◽  
Author(s):  
T.M. Smith ◽  
M.S. Hooshmand ◽  
B.D. Esser ◽  
F. Otto ◽  
D.W. McComb ◽  
...  
Keyword(s):  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Scale Characterization

Atomic-scale compositional characterization of a nanocrystalline AlCrCuFeNiZn high-entropy alloy using atom probe tomography

2013 ◽  
Vol 61 (12) ◽  
pp. 4696-4706 ◽  
Author(s):  
K.G. Pradeep ◽  
N. Wanderka ◽  
P. Choi ◽  
J. Banhart ◽  
B.S. Murty ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Compositional Characterization

Cyclic Plasticity of CoCrFeMnNi High-Entropy Alloy (HEA): A Molecular Dynamics Simulation

2021 ◽  
Vol 13 (01) ◽  
pp. 2150006
Author(s):  
Xin Du ◽  
Xiaochong Lu ◽  
Siyao Shuang ◽  
Zhangwei Wang ◽  
Qi-lin Xiong ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Atomic Scale ◽  
Dynamics Simulation ◽  
Cyclic Plasticity ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Lattice Disorder ◽  
Partial Dislocations ◽  
Effects Of Temperature

The CoCrFeMnNi high-entropy alloy (HEA) is a potential structural material, whose cyclic plasticity is essential for its safety assessment in service. Here, the effects of twin boundaries (TBs) and temperature on the cyclic plasticity of CoCrFeMnNi HEA were studied by the molecular dynamics (MD) simulation. The simulation results showed that a significant amount of lattice disorders were generated due to the interactions between partial dislocations in CoCrFeMnNi HEA during the cyclic deformation. Lattice disorder impeded the reverse movement of dislocations and then weakened Bauschinger’s effect in the HEA. The cyclic plasticity of CoCrFeMnNi HEA, especially Bauschinger’s effect, depends highly on the temperature and pre-existing TBs. Such dependence lies in the effects of temperature and pre-existing TBs on the extent of lattice disorder. This study helps further understand the cyclic plasticity of CoCrFeMnNi HEA from the atomic scale.

scholarly journals Atomic scale modelling of hexagonal structured metallic fission product alloys

2015 ◽  
Vol 2 (4) ◽  
pp. 140292 ◽  
Author(s):  
S. C. Middleburgh ◽  
D. M. King ◽  
G. R. Lumpkin
Keyword(s):  
Density Functional ◽  
Configurational Entropy ◽  
Principal Component ◽  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Scale Modelling ◽  
Entropy Effects ◽  
Mo Content ◽  
The Impact

Noble metal particles in the Mo-Pd-Rh-Ru-Tc system have been simulated on the atomic scale using density functional theory techniques for the first time. The composition and behaviour of the epsilon phases are consistent with high-entropy alloys (or multi-principal component alloys)—making the epsilon phase the only hexagonally close packed high-entropy alloy currently described. Configurational entropy effects were considered to predict the stability of the alloys with increasing temperatures. The variation of Mo content was modelled to understand the change in alloy structure and behaviour with fuel burnup (Mo molar content decreases in these alloys as burnup increases). The predicted structures compare extremely well with experimentally ascertained values. Vacancy formation energies and the behaviour of extrinsic defects (including iodine and xenon) in the epsilon phase were also investigated to further understand the impact that the metallic precipitates have on fuel performance.

scholarly journals The Nature of Lattice Distortion and Strengthening in High Entropy Alloy

2020 ◽  
Author(s):  
Jian-Min Zuo ◽  
Yu-Tsun Shao ◽  
Haw-Wen Hsiao ◽  
Qun Yang ◽  
Yang Hu ◽  
...  
Keyword(s):  
Lattice Distortion ◽  
Structural Diversity ◽  
Direct Consequence ◽  
Atomic Scale ◽  
Structural Basis ◽  
High Entropy Alloy ◽  
Structure Property ◽  
Theoretical Understanding ◽  
High Entropy ◽  
Chemical Disorder

Abstract High entropy alloys (HEAs) belong to a new class of materials with multiple principal components that are chemically concentrated in less explored phase spaces. Since the initial discovery, HEAs have attracted tremendous interest for their remarkable structural diversity and associated properties, including high strength and high ductility. Underlining the structural diversity is the metastability of HEAs, to which a key contributor is the lattice distortion effect that emerges as a direct consequence of interplay between atomic size misfits and chemical disorder. Lattice distortion also directly contributes to alloy strengthening and ductility. Despite the recognized significance, however, the critical knowledge of lattice distortion is still missing in the study of HEAs. Here, we first report on the nature of lattice and chemical disorder in a single-phase HEA and determine its local atomic structure. Our results uncover the manifestation of disorder at three different length scales, namely, the lattice distortion at the atomic scale, the chemical disorder at the nm scale, and the emergence of nanoscopic shear at the mesoscopic scale. The multiscale disorder leads to hierarchical strengthening, unlike anything that we know before about metals. This finding provides the structural basis for theoretical understanding of structure-property relationships in HEAs, and demonstrates the randomness of disorder as a new dimension for designing future strong and ductile alloys.

Atomic scale structural characterization of B2 phase precipitated along FCC twin boundary in a CoCrFeNiAl0.3 high entropy alloy

2019 ◽  
Vol 162 ◽  
pp. 161-165 ◽  
Author(s):  
Xiaodong Wang ◽  
Wei Zhou ◽  
Pan Liu ◽  
Shuangxi Song ◽  
Kolan Madhav Reddy
Keyword(s):  
Twin Boundary ◽  
Structural Characterization ◽  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy ◽  
B2 Phase

Atomic-scale analysis of nanoindentation behavior of high-entropy alloy

2016 ◽  
Vol 01 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Jia Li ◽  
QiHong Fang ◽  
Bin Liu ◽  
YouWen Liu ◽  
Yong Liu
Keyword(s):  
Mechanical Properties ◽  
Indentation Depth ◽  
Plastic Region ◽  
Indentation Test ◽  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Indentation Force ◽  
Elastic And Plastic Deformations ◽  
Dynamics Simulations

Using molecular dynamics simulations, we study the elastic and plastic deformations of indentation in FeCrCuAlNi high-entropy alloy (HEA). The indentation tests are carried out using spherical rigid indenter to investigate the effects of high-entropy and severe lattice distortion in terms of shear strain, indentation force, surface morphology, defect structure, dislocation evolution and radial distribution function on the deformation processes. It can be found that when the indentation depth increases, the shear stress requires for the occurrence of the contact area between the indenter and the substrate increased, which is attributable to a higher probability to observe the dislocation evolution under a large indentation depth. The indentation test also shows that the equal element addition can significantly improve the mechanical properties of HEA compared with the conventional alloy. Based on the Hertzian fitting, the FeCrCuAlNi HEA has the Young’s modulus of 161[Formula: see text]GPa and hardness of 15.4[Formula: see text]GPa, respectively. These values are higher than that of traditional metal materials, due to the low stacking fault energy and the dense atomic arrangement in the slip plane of HEA. In the plastic region, the Fe element causes the more stable crystal structure, much stronger than the Cu element, presumably resulted from a variety of crystal structures for Fe in the multicomponent FeCrCuAlNi alloy. Further, this effective strategy is used to accelerate the discovery of excellent mechanical properties of HEAs.

Atomic-scale homogenization in an fcc-based high-entropy alloy via severe plastic deformation

2016 ◽  
Vol 686 ◽  
pp. 15-23 ◽  
Author(s):  
Hao Yuan ◽  
Ming-Hung Tsai ◽  
Gang Sha ◽  
Fan Liu ◽  
Zenji Horita ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Atomic Scale ◽  
High Entropy Alloy ◽  
High Entropy
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