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SESSION:
AdvancedMaterialsTuePM3-R8
8th Intl Symposium on New & Advanced Materials and Technologies for Energy, Environment, Health and Sustainable Development
Tue. 22 Oct. 2024 / Room: Ariadni B
Session Chairs: Tetiana Prikhna; Amr Henni; Student Monitors: TBA

16:45: [AdvancedMaterialsTuePM311] OS
HIGH ENTROPY ALLOYS BY BALL MILLING AND ADIABATIC SHOCK WAVE CONSOLIDATION
Nikoloz Chikhradze1; Fernand D. S. Marquis2; Mikheil Chikhradze3; Davit Tsverava4
1G. Tsulukidze Mining Institute, Tbilisi, Georgia; 2United Nano Technologies (UNT) & Integrated Materials Technologies and Systems (IMTS), Seaside, United States; 3Georgian Technical University, Tbilisi, Georgia; 4LEPL Grigol Tsulukidze Mining Institute/Georgian Technical University, Tbilisi, Georgia
Paper ID: 270 [Abstract]

According to the latest definitions [1], High-Entropy Alloys (HEAs) are the alloys where the concentration of basic (at least 5) elements varies between 5-35%. The HEA has higher mixing entropy than the conventional alloys and intermetallic compounds and form the stabile solid solutions with disordered structure [1, 2, 3, 4, 5]. 

At the current stage the volume of investigations towards high entropy materials is extended from single phase solid solution structure to multi-phase structures, containing solid solution phases, intermetallic compounds, oxides, borides etc.  [6, 7, 8, 9]. 

Promised direction in this field are the high-entropy composites, prepared based on the HEAs matrix- reinforced with hard ceramic compounds. Reinforcement of HEA matrix by Intermetallic and ceramic compounds are additional tools/and challenge to improve/or design new properties of HEA based composites. Accordance evaluation “HEA is still in earlier stages hence a detailed investigation is needed” [8].  Especially, it should be underlined that HEAs, as the composite materials, are less investigated and the studies in that direction are now quite intensive. 

Accordingly, there is a huge potential to find new properties in the field of multi-component high-entropy nanostructure materials. 

The analyses show that the ball milling syntheses and adiabatic explosive compaction technologies are attractive methods for the synthesis of powdered and bulk high entropy nanocomposites [10].

In the study, mechanical alloying (MA), followed by adiabatic explosive consolidation was considered for sintering of bulk high entropy nanocomposites in Fe-W-Al-Ti-Ni–B-C system.  For MA the high energetic Planetary mill was used. The time of the processing was: 15; 30h. 36h; 48h and 72h. The ratio of balls to blend was 10:1. The phase composition and particle sizes of the powders were controlled by X-ray diffraction system and SEM. Industrial explosives, Ammonite, Powergel and Hexogen were used for adiabatic shock wave compaction of ball milled powder compositions. The MA nano blend was charged in Steel 3 alloy-tube container and at the first stage the pre-densification of the mixtures was performed by static press installation (intensity of loading P=500-1000 kg/cm2). The experiments were performed at room temperature. The shock wave pressure (loading intensity) varied in range: 3-20Gpa. The set conditions the explosive were detonated by electrical detonator. High pressure developed by explosive and temperature initiate the syntheses and consolidate the ball milled high entropy nanopowder composition. The compacting process accompanied with the syntheses and resulting in situ obtaining the bulk high entropy alloys. The phase analyses and structure-property of bulks HEA compact samples were studied. The obtained results and discussions are presented in the paper. 

References:
[1] Yeh J. et al, Nanostructured high entropy alloys with multiple principal elements: novel alloy design concepts and outcomes, Adv. Eng. Mater. V. 6., #5, 2004
[2] Michael C. Cao, Jien-Wei-Yeh, Peter K. Liaw, Youg Zhang, eBook: High-Entropy Alloys, Fundamentals and Applications, Springer, 2016
[3] High-Entropy Alloys, JOM, An official publication of The Minerals, Metals & Materials Society, Springer, November 2017
[4] Cantor B. et al., Materials Science and Engineering: A, 375-377, 213-218, 2004
[5] He Q. F. et al, Design of High-Entropy Alloy: A Perspective from Nonideal Mixing, JOM, v.69., # 11, p. 2092-2098, 2017
[6] Miracle D.B. High Entropy Alloys: A current Evaluation of Founding ideal Core Effects and Exploring “Nonlinear” Alloys, JOM, v.69., # 11, p. 2130-2136, 2017
[7] Li J, Combustion syntheses of High Entropy Materials and Thermoelectric Materials, Coimbra, 2017, http://www.ism.ac.ru/events/EPNM2016/presentations/16.pdf
[8] Weiping Chen et al., Alloying Behavior, microstructure and Mechanical properties of FeNiCrCo0.3Al0.7High Entropy Alloy, Materials and Design, v. 51 p. 854-860, 2013, https://www.sciencedirect.com/science/article/pii/S0261306913003841
[9]Prabakaras R. K. et al., Synthesis and Characterization of High Entropy Alloy (CrMnFeNiCu) Reinforced AA6061 Aluminum Matrix Composite, Mechanics and Mechanical Engineering, Vol. 21, No. 2 (2017) 415–424
[10] M. Chikhradze, G. Oniashvili, “Theoretical and Experimental Investigations of Shock wave induced reactions in Ti-Al System “International Journal of Powder Metallurgy, 2008


17:25 POSTERS/EXHIBITION - Ballroom Foyer