Impact of interstitial carbon on self-diffusion in CoCrFeMnNi high entropy alloys

2020 ◽  
Vol 188 ◽  
pp. 264-268
Author(s):  
O.A. Lukianova ◽  
Z. Rao ◽  
V. Kulitckii ◽  
Z. Li ◽  
G. Wilde ◽  
...  
Keyword(s):  
High Entropy Alloys ◽  
Interstitial Carbon ◽  
High Entropy ◽  
Self Diffusion

scholarly journals Effect of interstitial carbon on the evolution of early-stage irradiation damage in equi-atomic FeMnNiCoCr high-entropy alloys

2020 ◽  
Vol 127 (2) ◽  
pp. 025103 ◽  
Author(s):  
Eryang Lu ◽  
Ilja Makkonen ◽  
Kenichiro Mizohata ◽  
Zhiming Li ◽  
Jyrki Räisänen ◽  
...  
Keyword(s):  
Early Stage ◽  
Irradiation Damage ◽  
High Entropy Alloys ◽  
Interstitial Carbon ◽  
High Entropy

On the Self - and Impurity Diffusion in High Entropy Alloys

2018 ◽  
Vol 17 ◽  
pp. 105-114
Author(s):  
Dezső L. Beke ◽  
Gábor Erdélyi
Keyword(s):  
Melting Point ◽  
Tracer Diffusion ◽  
The Self ◽  
Impurity Diffusion ◽  
Diffusion Activation Energy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Self Diffusion ◽  
Law Of Corresponding States ◽  
Constituent Elements

General trends in self- and impurity diffusion data are analyzed in high entropy alloys. Our analysis is based on the similarity of inter-atomic potentials in metals, which is in fact equivalent to a three-parameter description of the system (the mass, m, the lattice spacing, a, and the melting point, Tm, are only used). This leads to the so-called law of corresponding states in metals, manifested in many empirical rules (e.g. compensation laws or the proportionality between the self-diffusion activation energy and the melting point) if one uses dimensionless/reduced variables (like the homologous temperature: T*=T/Tm). It was shown in our previous papers, using the concept of a hypothetical crystal composed of simple atomic species whose properties are an average of the components, that the tracer diffusion of any species (let it be either one of the constituent atoms or a foreign atom) can be considered as impurity diffusion in the pure many-component matrix. Using this concept, we illustrate that the diffusion coefficients, Di, follow the same rule which obtained for impurity diffusion in pure metals: lnDi=A(T*)(Tmi/Tm-1)+r, with the same fitting parameters A(T*) and r. According to this, the diffusion of the constituent elements in high entropy alloys indeed shows some sluggish character, which can be attributed to a more or less temperature independent factor.

High-Entropy Alloys as Catalysts for the CO2 and CO Reduction Reactions

2019 ◽  
Author(s):  
Jack Pedersen ◽  
Thomas Batchelor ◽  
Alexander Bagger ◽  
Jan Rossmeisl
Keyword(s):  
Density Functional ◽  
Rational Design ◽  
Hydrogen Adsorption ◽  
Co Adsorption ◽  
Reduction Reaction ◽  
Supervised Machine Learning ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Co Reduction ◽  
Disordered Alloy

Using the high-entropy alloys (HEAs) CoCuGaNiZn and AgAuCuPdPt as starting points we provide a framework for tuning the composition of disordered multi-metallic alloys to control the selectivity and activity of the reduction of carbon dioxide (CO2) to highly reduced compounds. By combining density functional theory (DFT) with supervised machine learning we predicted the CO and hydrogen (H) adsorption energies of all surface sites on the (111) surface of the two HEAs. This allowed an optimization for the HEA compositions with increased likelihood for sites with weak hydrogen adsorption{to suppress the formation of molecular hydrogen (H2) and with strong CO adsorption to favor the reduction of CO. This led to the discovery of several disordered alloy catalyst candidates for which selectivity towards highly reduced carbon compounds is expected, as well as insights into the rational design of disordered alloy catalysts for the CO2 and CO reduction reaction.

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
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