Cooling Rate and Size Effect on the Microstructure and Mechanical Properties of AlCoCrFeNi High Entropy Alloy

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
F. J. Wang ◽  
Y. Zhang ◽  
G. L. Chen ◽  
H. A. Davies
Keyword(s):  
Solid Solution ◽  
Atomic Ratio ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Body Centered Cubic ◽  
Mechanical Behaviors ◽  
High Entropy ◽  
Intermediate Phases ◽  
Different Diameters ◽  
Very High

High entropy alloys are usually defined as the kind of alloys with at least five principle components, each component has the equi-atomic ratio or near equi-atomic ratio, and the high entropy alloys can have very high entropy of mixing, forming simple solid solution rather than many complex intermediate phases. In this paper, the size effects on the microstructure and mechanical behaviors of a high entropy alloy of AlCoCrFeNi was studied by preparing as-cast rod samples with different diameters. The alloy independent of cast diameter samples has the same phase of body centered cubic solid solution. With decreasing casting diameter, both the strength and the plasticity are increased slightly.

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

High Entropy Based Composites - An Overview

2019 ◽  
Vol 969 ◽  
pp. 98-103
Author(s):  
T. Ram Prabhu ◽  
Yash Chodancar ◽  
M. Arivarasu ◽  
N. Arivazhagan ◽  
R.K. Mishra
Keyword(s):  
Solid Solution ◽  
Short Note ◽  
Atomic Ratio ◽  
Fatigue Properties ◽  
High Entropy Alloy ◽  
Matrix Composites ◽  
Essential Information ◽  
High Entropy ◽  
Potential Applications ◽  
Processing Techniques

High entropy alloy (HEA) is a new class of alloy that has a different alloy design concept over the conventional dilute alloys. In this alloy, the alloying elements have an equi-atomic ratio that helps to increase the entropy of the alloy to stabilize the simple solid solution (BCC, FCC and HCP) over the intermetallics. The stabilization of solid solution improves the paradoxial properties such as strength and toughness. High thermal stability, excellent creep and fatigue properties, outstanding corrosion resistance are the attractive features of HEA. Recently, the HEA is explored as a matrix or particle in the metal matrix composites. Research studies on HEA based composites are plenty and scattered. In this work, we attempt to collate essential information in the HEA based composites. The overview covers (1) processing techniques, (2) microstructure characterization and (3) the mechanical properties in detail. A short note on the potential applications of HEA based composites is also proposed.

scholarly journals Effect of Mo Addition on The Microstructure and Mechanical Properties of CoCuFeNi High Entropy Alloy

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1017
Author(s):  
Yang Shao ◽  
Huan Ma ◽  
Yibing Wang
Keyword(s):  
Mechanical Properties ◽  
Solution Structure ◽  
Tensile Tests ◽  
Atomic Ratio ◽  
Vacuum Arc ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Microstructure And Mechanical Properties ◽  
Mo Content

In order to reveal the effect of Mo addition on the microstructure and mechanical properties, (CoCuFeNi)100-xMox (x = 0, 10, 15, 19, and 25, x values in atomic ratio) high entropy alloys were prepared by vacuum arc-melting. The results showed that with Mo addition, the μ phase formed and serious separation occurred in the high entropy alloys. The content of μ phase increased with the increase in Mo content. The microstructure of the alloys changed from an initial single-phase face-center-cubic (FCC) solid solution structure (x = 0) to a hypoeutectic microstructure (x = 15), then to a full eutectic microstructure (x = 19), and finally to a hypereutectic microstructure (x = 25). Coherent interface between μ phase and FCC phase was observed. The (CoCuFeNi)81Mo19 alloy with fully eutectic microstructures exhibited the highest yield strength of 557 MPa and fracture strength of 767 MPa in tensile tests at room temperature. The fracture surface revealed that the formation of great amounts of the μ phase resulted in the loss of ductility of (CoCuFeNi)100-xMox alloys.

scholarly journals Plastic deformation of solid-solution strengthened Hf-Nb-Ta-Ti-Zr body-centered cubic medium/high-entropy alloys

2021 ◽  
Vol 200 ◽  
pp. 113927
Author(s):  
Rajeshwar R. Eleti ◽  
Nikita Stepanov ◽  
Nikita Yurchenko ◽  
Denis Klimenko ◽  
Sergey Zherebtsov
Keyword(s):  
Solid Solution ◽  
Plastic Deformation ◽  
High Entropy Alloys ◽  
Body Centered Cubic ◽  
High Entropy

scholarly journals Thermal Stability of MoNbTaVW High Entropy Alloy Thin Films

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 941
Author(s):  
Ao Xia ◽  
Robert Franz
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
High Entropy Alloy ◽  
Solid Solution Phase ◽  
Body Centered Cubic ◽  
High Entropy ◽  
Thermal Stability Of

Refractory high entropy alloys are an interesting material class because of their high thermal stability, decent electrical conductivity, and promising mechanical properties at elevated temperature. In the present work, we report on the thermal stability of body-centered cubic MoNbTaVW solid solution thin films that were synthesized by cathodic arc deposition. After vacuum annealing up to 1600 °C, the morphology, chemical composition, crystal structure, and electrical conductivity, as well as the mechanical properties, were analyzed. The observed body-centered cubic MoNbTaVW solid solution phase is stable up to 1500 °C. The evolution of electrical and mechanical properties due to the annealing treatment is discussed based on the observed structural changes of the synthesized thin films.

Selection of High Entropy Alloy for Solid Solution Using Multi-Criteria Decision Making Tool

2019 ◽  
Vol 969 ◽  
pp. 466-471
Author(s):  
Vinay Kumar Soni ◽  
Shubhashis Sanyal ◽  
Sudip Kumar Sinha
Keyword(s):  
Solid Solution ◽  
Vital Role ◽  
Size Difference ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Atomic Size Difference ◽  
Topological Parameter ◽  
Topsis Technique ◽  
Selection Of

High entropy alloys (HEA’s) have found a very special place in aerospace industries due to their property of forming solid solution. In past literatures on high entropy alloys, it is established that parameters like atomic size difference (), topological parameter (Ω) and electro-negativity difference (∆) plays a vital role in deciding whether solid solution will be formed or not. Therefore, the present study deals with the selection of optimal high entropy composition based on the three parameters δ, Ω and with the help of TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Ranking is done for 38 HEA different compositions such that the first rank represents the HEA which is most likely to form solid solution. The study reveals that TOPSIS method can be successfully implemented to predict the formation of solid solution in HEA’s.

scholarly journals Brute Force Composition Scanning with a CALPHAD Database to Find Low Temperature Body Centered Cubic High Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 911 ◽  
Author(s):  
T. Klaver ◽  
D. Simonovic ◽  
M. Sluiter
Keyword(s):  
Low Temperature ◽  
Grid Point ◽  
Ternary Alloys ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Body Centered Cubic ◽  
High Entropy ◽  
Increasing Temperature ◽  
Bcc Phase

We used the Thermo-Calc High Entropy Alloy CALPHAD database to determine the stable phases of AlCrMnNbTiV, AlCrMoNbTiV, AlCrFeTiV and AlCrMnMoTi alloys from 800 to 2800 K. The concentrations of elements were varied from 1–49 atom%. A five- or six-dimensional grid is constructed, with stable phases calculated at each grid point. Thermo-Calc was used as a massive parallel tool and three million compositions were calculated, resulting in tens of thousands of compositions for which the alloys formed a single disordered body centered cubic (bcc) phase at 800 K. By filtering out alloy compositions for which a disordered single phase persists down to 800 K, composition ‘islands’ of high entropy alloys are determined in composition space. The sizes and shapes of such islands provide information about which element combinations have good high entropy alloy forming qualities as well as about the role of individual elements within an alloy. In most cases disordered single phases are formed most readily at low temperature when several elements are almost entirely excluded, resulting in essentially ternary alloys. We determined which compositions lie near the centers of the high entropy alloy islands and therefore remain high entropy islands under small composition changes. These island center compositions are predicted to be high entropy alloys with the greatest certainty and make good candidates for experimental verification. The search for high entropy islands can be conducted subject to constraints, e.g., requiring a minimum amount of Al and/or Cr to promote oxidation resistance. Imposing such constraints rapidly diminishes the number of high entropy alloy compositions, in some cases to zero. We find that AlCrMnNbTiV and AlCrMoNbTiV are relatively good high entropy alloy formers, AlCrFeTiV is a poor high entropy alloy former, while AlCrMnMoTi is a poor high entropy alloy former at 800 K but quickly becomes a better high entropy alloy former with increasing temperature.

Microstructure and Wear Resistance of FeNiCrMnCu High Entropy Alloy

2017 ◽  
Vol 1143 ◽  
pp. 3-6 ◽  
Author(s):  
Gheorghe Buluc ◽  
Iulia Florea ◽  
Romeu Chelariu ◽  
Oana Rusu ◽  
Ioan Carcea
Keyword(s):  
Solid Solution ◽  
Wear Resistance ◽  
Materials Science ◽  
Microstructural Analysis ◽  
Main Element ◽  
High Entropy Alloy ◽  
Test Machine ◽  
High Entropy Alloys ◽  
Metallic Elements ◽  
High Entropy

In this paper it is presented the microstructure and wear resistance of FeNiCrMnCu high entropy alloy. High entropy alloys are composed by at least five metallic elements in equimolar or non-equimolare proportions. High entropy alloys a brand new category of metallic materials, appeared to be a new effort in materials science and engineering, which attracted great interest. To obtain FeNiCrMnCu high entropy alloy we used an 8000 Hz induction furnace. The chemical composition was determined by EDAX. Microstructural analysis was performed using optical microscopy and SEM (scanning electron microscopy), which showed that the FeNiCrMnCu high entropy alloy has a dentritic structure and form a solid solution. Choosing copper as the main element (copper tends to segregate in interdentritic region due to its positive enthalpy of mixing with many common elements) [1], along with the iron, nickel, chromium and manganese, led to obtaining a dentritic structure specify for solid solution, which, however, did not lead to a significant hardness for FeNiCrMnCu high entropy alloy. In this work we selected pure metallic elements like: Fe, Ni, Cr, Mn and Cu. The quantity of alloy developed has 1.5 kg. Friction and wear resistance were the studied by using a reciprocating sliding test machine, in a pin on disk configuration, using aluminum as counter face. Hardness value regarding FeNiCrMnCu high entropy alloy was 184 HV and medium friction coefficient value for FeNiCrMnCu high entropy alloys was 0.86 for 28 minutesc and 1.13 for the first 20 seconds.

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