A eutectic high-entropy alloy with seven components (Fe, Ni, Cr, V, Co, Mn, and Nb) was designed via the melt route guided by CALPHAD predictions. Configurational entropy estimated for the two-phase microstructure qualifies it to be referred to as a high-entropy alloy. When the Nb content exceeded 9.7 at. pct, the microstructure changed from hypoeutectic with primary face-centered cubic phase to hypereutectic with primary Laves phase. © 2019, The Minerals, Metals & Materials Society and ASM International.

Phanikumar Gandham

Department of Metallurgical and Materials Engineering

M. R. Rahul

entropy

Eutectics

microstructure

CALPHAD

CONFIGURATIONAL ENTROPY

FACE CENTERED CUBIC PHASE

LAVES-PHASE

TWO-PHASE MICROSTRUCTURES

HIGH-ENTROPY ALLOYS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

High entropy alloys with multiple phases are taken for undercooling studies and established the microstructure evolution with respect to undercooling. The melt fluxing technique was used for the current study to achieve undercooling. Predictions on the equilibrium phase formation of these systems was performed using CALPHAD approach and compared with experimental observations. Metastable microstructures were observed during undercooling and the morphological changes could be correlated with the currently established mechanisms. The detailed microstructure evolution in FeCoNiCuX0.5 (X = Al, Mo, Ti, W, Zr) shows the minute addition of these elements results in variation in microstructure evolution during as cast as well as undercooled condition. The studied systems show a maximum undercooling of more than 0.18 TL. and maintained crystalline nature even in deep undercooling. The segregation nature of elements was studied and correlated with the phase field simulations obtained. © 2019 Elsevier B.V.

Journal of Alloys and Compounds

Metastable microstructures in the solidification of undercooled high entropy alloys

Studies on solidification of equiatomic multi-component alloys are essential in developing melt-route processing of high entropy alloys. The extent of undercooling during processing controls microstructure evolution. In this study, we present solidification studies on undercooled equiatomic FeCuNi alloy carried out using melt fluxing technique. The alloy shows a two-phase (FCC + FCC) microstructure even at deep undercooling of more than 200 K. The dendrite growth velocity measured using high-speed video imaging shows a nonlinear increase in growth velocity with the increase in the extent of undercooling. A modified dendritic growth model was able to predict the growth velocity. The segregation behaviour and microstructures at different extents of undercooling can be predicted using phase field simulation. © 2019 Elsevier B.V.

Solidification behaviour of undercooled equiatomic FeCuNi alloy

Hot deformation behaviour of AlCoCrFeNi2.1 eutectic high entropy alloy, consisting of fcc (CoCrFe-rich) and BCC (NiAl-rich) phases is studied by generating contour maps of multiple models using high temperature thermo-mechanical simulator compression test data. The workability regimes for thermomechanical processing are identified as 1073–1150 K and 10−3– 10−2.2s−1 as well as 1338–1373 K and 10−3–10−1.2 s−1. Finite element simulation has been used to study the strain distribution and material flow during hot deformation, which assists for predicting actual material flow in forging process. Flow instabilities during hot forming has been avoided by adopting integrated approach. © 2018 Elsevier B.V.

Experimental and finite element simulation studies on hot deformation behaviour of AlCoCrFeNi2.1 eutectic high entropy alloy

Multicomponent Co20Cu20Fe20Ni20Ti20 eutectic high entropy alloy (HEA), processed by vacuum arc melting cum suction casting technique was studied. The microstructure of this eutectic HEA consists bcc (β) and fcc (α2) solid solution dendritic phases and eutectics (fcc (α1) plus Ti2(Ni, Co)-type Laves phase). Serrations in the flow behaviour are attributed to multi substitutional solutes in the multi-phase microstructure. Based on the detailed analysis of mechanical data together with deformed microstructural characterization, the optimum thermo-mechanical processing conditions for hot working are identified as T=930-990 °C (1203-1263 K) and strain rate range of 10-3 s-1-10-1 s-1. © 2016 Elsevier B.V.

Materials Science and Engineering A

Hot deformation behaviour and processing map of Co-Cu-Fe-Ni-Ti eutectic high entropy alloy

Journal of Materials Research

Effect of Nb content on thermal stability, mechanical and corrosion behaviors of hypoeutectic CoCrFeNiNbχ high-entropy alloys

Materials & Design

A new strategy to design eutectic high-entropy alloys using simple mixture method

Intermetallics

A new strategy to design eutectic high-entropy alloys using mixing enthalpy

Design of a Seven-Component Eutectic High-Entropy Alloy

Journal	Data powered by TypesetMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Publisher	Data powered by TypesetSpringer Boston
ISSN	10735623
Open Access	No