https://dc.engconfintl.org/cgi/viewcontent.cgi?article=1032&context=superalloys_ii

A critical review of high entropy alloys and related concepts

High-entropy alloys (HEAs) are a relatively new class of materials that have gained considerable attention from the metallurgical research community over recent years They are characterised by their unconventional compositions, in that they are not based around a single major component, but rather comprise multiple principal alloying elements Four core effects have been proposed in HEAs: (1) the entropic stabilisation of solid solutions, (2) the severe distortion of their lattices, (3) sluggish diffusion kinetics and (4) that properties are derived from a cocktail effect By assessing these claims on the basis of existing experimental evidence in the literature, as well as classical metallurgical understanding, it is concluded that the significance of these effects may not be as great as initially believed The effect of entropic stabilisation does not appear to be overarching, insufficient evidence exists to establish the strain in the lattices of HEAs, and rapid precipitation observed in some HEAs sug

https://www.tandfonline.com/doi/pdf/10.1080/09506608.2016.1180020

High-entropy alloys: a critical assessment of their founding principles and future prospects

Microstructural origins of high strength and high ductility in an AlCoCrFeNi 2.1 eutectic high-entropy alloy

Multicomponent high-entropy Cantor alloys

Phase prediction in high entropy alloys with a rational selection of materials descriptors and machine learning models

First-principles studies of the structural, elastic, electronic and thermal properties of Ni3Nb

According to the experimental dataset on the as cast high entropy alloys with cubic structure, the relationship between the stability and physical parameters of cubic structure has been investigated from the view of the atomic size difference, mixing enthalpy, electronegativity difference and valence electron concentration in the present work to reveal the stability and structure formation in as cast high entropy alloys. The results indicated that the mixing enthalpy is the effective parameter that can predict the stability of solid solutions in as cast high entropy alloys. The atomic size difference, electronegativity difference and valence electron concentration also play important roles in the formation of body centred cubic and face centred cubic crystals. Moreover, the back propagation artificial neural network was established using data collected from the calculated solid solution physical parameters and the structure characteristic of as cast high entropy alloys, and the structure of alloys...

Stability and structure prediction of cubic phase in as cast high entropy alloys

First-principles study of NiAl alloyed with Co

The structural, elastic and electronic properties of nonmagnetic TiCr 2 , TiMn 2 and antiferromagnetic TiFe 2 with hexagonal C14 structure were investigated by mean of the first-principles calculations within the frame work of density functional theory (DFT). The calculated lattice constants were in good agreement with the experimental values. The obtained cohesive energy and formation enthalpy showed TiCr 2 , TiMn 2 and TiFe 2 are of the structural stability from the energetic point of view. The five independent elastic constants were calculated, showing that these compounds are mechanically stable. Then the polycrystalline elastic parameters (bulk modulus B , shear modulus G , Young's modulus E , and Poisson's ratio ν ) were obtained by using the Voigt–Reuss–Hill (V–R–H) approximation, and the ductility and plasticity of these compounds were further analyzed. The elastic anisotropy of these compounds was also discussed in details. Finally, the electronic density of states (DOS) and charge density distribution were also calculated, indicating the existence of a combination of metallic, covalent and ionic bonding in these C14 compounds.

Yong Cao

Papers

First-principles studies of the structural, elastic, electronic and thermal properties of Ni3Nb

Stability and structure prediction of cubic phase in as cast high entropy alloys

First-principles study of NiAl alloyed with Co

A first-principles study on the structural, elastic and electronic properties of the C14 Laves phase compounds TiX2 (X=Cr, Mn, Fe)

First-principles study of hydrogen storage and diffusion in B2 FeTi alloy