scholarly journals Role of configurational entropy in body-centred cubic or face-centred cubic phase formation in high entropy alloys

2016 ◽  
Vol 124 ◽  
pp. 90-94 ◽  
Author(s):  
G. Anand ◽  
R. Goodall ◽  
Colin L. Freeman
Keyword(s):  
Phase Formation ◽  
Configurational Entropy ◽  
Cubic Phase ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Kinetically Limited Phase Formation of Pt-Ir Based Compositionally Complex Thin Films

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2298
Author(s):  
Aparna Saksena ◽  
Dimitri Bogdanovski ◽  
Hrushikesh Sahasrabuddhe ◽  
Denis Music ◽  
Jochen M. Schneider
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Surface Diffusion ◽  
Phase Formation ◽  
Single Phase ◽  
Configurational Entropy ◽  
High Entropy Alloys ◽  
X Ray ◽  
High Entropy ◽  
Two Phases

The phase formation of PtIrCuAuX (X = Ag, Pd) compositionally complex thin films is investigated to critically appraise the criteria employed to predict the formation of high entropy alloys. The formation of a single-phase high entropy alloy is predicted if the following requirements are fulfilled: 12 J∙K−1 mol−1 ≤ configurational entropy ≤ 17.5 J∙K−1 mol−1, −10 kJ∙mol−1 ≤ enthalpy of mixing ≤ 5 kJ∙mol−1 and atomic size difference ≤ 5%. Equiatomic PtIrCuAuX (X = Ag, Pd) fulfill all of these requirements. Based on X-ray diffraction and energy-dispersive X-ray spectroscopy data, near-equiatomic Pt22Ir23Cu18Au18Pd19 thin films form a single-phase solid solution while near-equiatomic Pt22Ir23Cu20Au17Ag18 thin films exhibit the formation of two phases. The latter observation is clearly in conflict with the design rules for high entropy alloys. However, the observed phase formation can be rationalized by considering bond strengths and differences in activation energy barriers for surface diffusion. Integrated crystal orbital Hamilton population values per bond imply a decrease in bond strength for all the interactions when Pd is substituted by Ag in PtIrCuAuX which lowers the surface diffusion activation energy barrier by 35% on average for each constituent. This enables the surface diffusion-mediated formation of two phases, one rich in Au and Ag and a second phase enriched in Pt and Cu. Hence, phase formation in these systems appears to be governed by the complex interplay between energetics and kinetic limitations rather than by configurational entropy.

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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