Study on properties of single-phase high entropy alloys with FCC structure based on the empirical electron theory

2021 ◽  
pp. 162892
Author(s):  
Xinpeng Guo ◽  
Yongquan Guo ◽  
Linhan Yin
Keyword(s):  
Single Phase ◽  
High Entropy Alloys ◽  
Electron Theory ◽  
High Entropy ◽  
Empirical Electron Theory ◽  
Fcc Structure

The Valence Electron Structure of High-Entropy Alloys

2017 ◽  
Vol 1142 ◽  
pp. 3-7
Author(s):  
Bo Cheng ◽  
Yun Kai Li ◽  
Gui Qin Hou
Keyword(s):  
Valence Electron ◽  
Electron Pair ◽  
Electron Structure ◽  
High Entropy Alloys ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
High Entropy ◽  
Melting Temperatures ◽  
Empirical Electron Theory ◽  
Pair Number

Empirical Electron Theory in Solids and Molecules (EET) was used to analyze the valence electron structure of ZrTiHfVNb, ZrTiHfVTa and ZrTiHfNbMo high-entropy alloys. The parameters characterizing the valence electron structure of high-entropy alloys were calculated, which were used to discuss the hardness and melting temperature of high-entropy alloys. The results show that the hardness of high-entropy alloys is positively correlated to the shared electron pair number in valence electron structure. The theoretical melting temperatures of high-entropy alloys were predicted by the parameters characterizing the valence electron structure.

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.

scholarly journals Al, Cu and Zr Addition to High Entropy Alloys: The Effect on Recrystallization Temperature

2018 ◽  
Vol 941 ◽  
pp. 1137-1142
Author(s):  
Elena Colombini ◽  
Andrea Garzoni ◽  
Roberto Giovanardi ◽  
Paolo Veronesi ◽  
Angelo Casagrande
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Single Phase ◽  
Boundary Energy ◽  
Cold Deformation ◽  
Recrystallization Temperature ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Ni Alloy ◽  
Sluggish Diffusion

The equimolar Cr, Mn, Fe, Co and Ni alloy, first produced in 2004, was unexpectedly found to be single-phase. Consequently, a new concept of materials was developed: high entropy alloys (HEA) forming a single solid-solution with a near equiatomic composition of the constituting elements. In this study, an equimolar CoCrFeMnNi HEA was modified by the addition of 5 at% of either Al, Cu or Zr. The cold-rolled alloys were annealed for 30 minutes at high temperature to investigate the recrystallization kinetics. The evolution of the grain boundary and the grain size were investigated, from the as-cast to the recrystallized state. Results show that the recrystallized single phase FCC structures exhibits different twin grains density, grain size and recrystallization temperatures as a function of the at.% of modifier alloying elements added. In comparison to the equimolar CoCrFeMnNi, the addition of modifier elements increases significantly the recrystallization temperature after cold deformation. The sluggish diffusion (typical of HEA alloys), the presence of a solute in solid solution as well as the low twin boundary energy are responsible for the lower driving force for recrystallization.

scholarly journals Shear localization of fcc high-entropy alloys

2018 ◽  
Vol 183 ◽  
pp. 03028 ◽  
Author(s):  
Marc A. Meyers ◽  
Zezhou Li ◽  
Shiteng Zhao ◽  
Bingfeng Wang ◽  
Yong Liu ◽  
...  
Keyword(s):  
Shear Strain ◽  
Single Phase ◽  
Dynamic Compression ◽  
Impact Resistance ◽  
Shear Localization ◽  
Solid Solution Hardening ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Work Hardening Rate ◽  
High Work

Dynamic behavior of the single phase (fcc) Al0.3CoCrFeNi and CoCrFeMnNi high-entropy alloys (HEAs) was examined. The combination of multiple strengthening mechanisms such as solid solution hardening, cutting forest dislocation, as well as mechanical nano-twinning leads to a high work-hardening rate, compared with conventional alloys. The resistance to shear localization was studied by dynamicallyloading hat-shaped specimens to induce forced shear localization. However, no adiabatic shear band could be observed for Al0.3CoCrFeNi HEA at a large shear strain ~1.1. Additionally, shear localization of the CoCrFeMnNi HEA was only found at an even larger shear strain ~7 under dynamic compression. It is therefore proposed that the combination of the excellent strain-hardening ability and modest thermal softening of these two kinds of high-entropy alloys gives rise to remarkable resistance to shear localization, which makes HEAs excellent candidates for impact resistance applications.

scholarly journals Investigation of Clusters and Their Effect on Grain Growth in Single Phase AlxCoCrFeNi High Entropy Alloys

2018 ◽  
Vol 24 (S1) ◽  
pp. 2214-2215
Author(s):  
Bharat Gwalani ◽  
Riyadh Salloom ◽  
Talukder Alam ◽  
Sheena V. Grace ◽  
Srivilliputhur Srinivasan ◽  
...  
Keyword(s):  
Grain Growth ◽  
Single Phase ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Criteria for Predicting the Formation of Single-Phase High-Entropy Alloys

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Claudia Troparevsky ◽  
James R. Morris ◽  
Paul R. C. Kent ◽  
Andrew R. Lupini ◽  
G. Malcolm Stocks
Keyword(s):  
Single Phase ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Prediction of Strength and Ductility in Partially Recrystallized CoCrFeNiTi0.2 High-Entropy Alloy

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 389 ◽  
Author(s):  
Hanwen Zhang ◽  
Peizhi Liu ◽  
Jinxiong Hou ◽  
Junwei Qiao ◽  
Yucheng Wu
Keyword(s):  
Tensile Strength ◽  
Single Phase ◽  
Volume Fraction ◽  
Tensile Elongation ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Number Density ◽  
High Entropy ◽  
Average Size ◽  
Strength And Ductility

The mechanical behavior of a partially recrystallized fcc-CoCrFeNiTi0.2 high entropy alloys (HEA) is investigated. Temporal evolutions of the morphology, size, and volume fraction of the nanoscaled L12-(Ni,Co)3Ti precipitates at 800 °C with various aging time were quantitatively evaluated. The ultimate tensile strength can be greatly improved to ~1200 MPa, accompanied with a tensile elongation of ~20% after precipitation. The temporal exponents for the average size and number density of precipitates reasonably conform the predictions by the PV model. A composite model was proposed to describe the plastic strain of the current HEA. As a consequence, the tensile strength and tensile elongation are well predicted, which is in accord with the experimental results. The present experiment provides a theoretical reference for the strengthening of partially recrystallized single-phase HEAs in the future.

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