Criteria for laves-phase formation in refractory high-entropy alloys

2021 ◽  
pp. 1-17
Author(s):  
Hongwei Yao ◽  
Dongxu Qiao ◽  
Junwei Miao ◽  
Jun Wang ◽  
Enyu Guo ◽  
...  
Keyword(s):  
Phase Formation ◽  
Laves Phase ◽  
High Entropy Alloys ◽  
High Entropy

Laves-phase formation criterion for high-entropy alloys

2016 ◽  
Vol 33 (1) ◽  
pp. 17-22 ◽  
Author(s):  
N. Yurchenko ◽  
N. Stepanov ◽  
G. Salishchev
Keyword(s):  
Phase Formation ◽  
Laves Phase ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Laves Phase Formation in High Entropy Alloys

2021 ◽  
Author(s):  
Roman Ryltsev ◽  
Svetlana Estemirova ◽  
Evgenii Sterkhov ◽  
Lubov Cherepanova ◽  
Denis Yagodin ◽  
...  
Keyword(s):  
Phase Formation ◽  
Single Phase ◽  
Laves Phase ◽  
Structural Defects ◽  
Clear Understanding ◽  
High Entropy Alloys ◽  
Laves Phases ◽  
Important Conclusion ◽  
High Entropy ◽  
Chemical Complexity

One of the intriguing recent results in the field of high-entropy alloys is the discovery of single-phase equiatomic multi-component Laves intermetallics. However, there is no clear understanding that a combination of chemical elements will form such high-entropy compounds. Here we contribute to understanding this issue by modifying the composition of duodenary TiZrHfNbVCrMoMnFeCoNiAl (12x) alloy in which we recently reported the fabrication of hexagonal C14 Laves phase. We consider three alloys based on 12x: 7x=12x-VCrMoMnFe, 12x+Sc, 12x+Be and observe that all of them crystalize with the formation of C14 Laves phase as a dominant structure. We report that 12x+Be alloy reveals single-phase C14 structure with very high concentration of structural defects and ultra-fine dendritic microstructure with almost homogenous distribution of the constituted elements over the alloy matrix. The 7x and 12x+Sc alloys contain C14 as a main phase and unknown impurity phases. To characterize the materials, we examine their heat capacity, electrical conductivity and magnetic properties. The measurements reveal that the Laves phases are Curie-Weiss paramagnets, which demonstrate metallic conduction; 7x and 12x alloys also reveal a pronounced Kondo-like anomaly. Analysis of experimental data as well as ab initio calculations suggests that chemical complexity and compositional disorder cause strong s-d band scattering and thus the rather high density of d-states in the conduction band. Analysis of the results suggests that the mechanism of Laves phase formation in multicomponent multi-principal element metallic alloys is may be the same as in polydisperse hardspheres mixtures. Another important conclusion is that the configurational entropy is a negligible factor in the stabilization of multi-element Laves phases.

Effect of Ta Addition on Microstructure and Hardness of FeCrNiMnCoTax and Al0.5FeCrNiMnCoTax High-Entropy Alloys

2016 ◽  
Vol 846 ◽  
pp. 13-19 ◽  
Author(s):  
Siti Sarah Mohd Pauzi ◽  
Mohamad Kamal Harun ◽  
Mahesh Talari
Keyword(s):  
Phase Formation ◽  
Intermetallic Phase ◽  
Laves Phase ◽  
Molar Ratio ◽  
High Entropy Alloys ◽  
Strengthening Effect ◽  
High Entropy ◽  
Arc Melting ◽  
Melting Technique ◽  
A Minor

Phase formation, microstructure, and hardness properties of FeCrNiMnCoTax and Al0.5 FeCrNiMnCoTax high-entropy alloys (HEA) have been investigated and reported. In this study, FeCrNiMnCoTax and Al0.5FeCrNiMnCoTax high-entropy alloys (HEA) were synthesized using arc-melting technique in argon (Ar) atmosphere from high purity elements (x in molar ratio, x=0.2, x=0.4 and x=0.6). Ingots from arc-melting were homogenized for 24h at 900°C in Ar atmosphere. Dominant dendritic and inter-dendritic phases were identified from the electron micrographs of these HEA. The area of inter-dendrite region increased for both FeCrNiMnCoTax and Al0.5FeCrNiMnCoTax alloys with the increasing of Ta content. The major phases in both FeCrNiMnCoTax and Al0.5FeCrNiMnCoTax alloys were identified as FCC and BCC solid-solutions. Addition of Al in Al0.5FeCrNiMnCoTax alloys has resulted in precipitation of a minor phase which was identified as FCC-TaCr2 Laves phase. As the Ta content increased, hardness of FeCrNiMnCoTax and Al0.5FeCrNiMnCoTax alloys increased from 200.34 Hv to 345.10 Hv and 385.22 Hv to 570.86 Hv respectively. Furthermore, presence of Laves phase in Al0.5FeCrNiMnCoTax alloys has resulted in higher hardness values compared to Al free sample, and this higher hardness could be attributed to precipitation strengthening effect by Laves intermetallic phase formation.

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.

Topologically Close-packed Phase Formation in High Entropy Alloys: A Review of Calphad and Experimental Results

JOM ◽  
2017 ◽  
Vol 69 (11) ◽  
pp. 2113-2124 ◽  
Author(s):  
K. Guruvidyathri ◽  
K. C. Hari Kumar ◽  
J. W. Yeh ◽  
B. S. Murty
Keyword(s):  
Phase Formation ◽  
Experimental Results ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Topologically Close Packed

Big-data analysis of phase-formation rules in high-entropy alloys

2017 ◽  
Vol 24 (4) ◽  
pp. 358-365 ◽  
Author(s):  
Wan-li Zhao ◽  
Ding-hao Miao ◽  
Yong Zhang ◽  
Zhan-bing He
Keyword(s):  
Big Data ◽  
Data Analysis ◽  
Phase Formation ◽  
Big Data Analysis ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals A Criterion for Topological Close-Packed Phase Formation in High Entropy Alloys

Entropy ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 2355-2366 ◽  
Author(s):  
Yiping Lu ◽  
Yong Dong ◽  
Li Jiang ◽  
Tongmin Wang ◽  
Tingju Li ◽  
...  
Keyword(s):  
Phase Formation ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Effects of La on Thermal Stability, Phase Formation and Magnetic Properties of Fe–Co–Ni–Si–B–La High Entropy Alloys

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1907
Author(s):  
Jiaming Li ◽  
Jianliang Zuo ◽  
Hongya Yu
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Phase Formation ◽  
Crystallization Temperature ◽  
High Entropy Alloys ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
High Entropy ◽  
Bcc Phase

The microstructure, phase formation, thermal stability and soft magnetic properties of melt-spun high entropy alloys (HEAs) Fe27Co27Ni27Si10−xB9Lax with various La substitutions for Si (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) were investigated in this work. The Fe27Co27Ni27Si10−xB9La0.6 alloy shows superior soft magnetic properties with low coercivity Hc of ~7.1 A/m and high saturation magnetization Bs of 1.07 T. The content of La has an important effect on the primary crystallization temperature (Tx1) and the secondary crystallization temperature (Tx2) of the alloys. After annealing at relatively low temperature, the saturation magnetization of the alloy increases and the microstructure with a small amount of body-centered cubic (BCC) phase embedded in amorphous matrix is observed. Increasing the annealing temperature reduces the magnetization due to the transformation of BCC phase into face-centered cubic (FCC) phase.

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