ORALS

SESSION: ManufacturingThuAM-R2	2nd Intl. Symp.on Advanced Manufacturing for Sustainable Development
Thu Oct, 24 2019 / Room: Leda (99/Mezz. F)
Session Chairs: Fernand Marquis; Nikoloz Chikhradze; Session Monitor: TBA

11:20: [ManufacturingThuAM01] Keynote
Advances in Synthesis and Densification of Heterogeneous Ultrafine and Nanostructured Materials and Applications in Components and Devices
Fernand D. S. Marquis¹ ; Nikoloz Chikhradze² ; Tetiana Prikhna³ ; Eugene Olevsky¹ ; ¹San Diego State University, San Diego, United States; ²G. Tsulukidze Mining Institute, Tbilisi, Georgia; ³Institute for Superhard Materials, Kiev, Ukraine;
Paper Id: 456 [Abstract]

Because the strength, toughness and other engineering properties of heterogeneous materials are strong dependent on their grain size and density, the quest to achieve simultaneously dense and fine, ultrafine and nanostructured grain size materials has been one of the most important in materials science and engineering. In this work we explore novel approaches for producing dense and fine, ultrafine and nanostructured heterogeneous materials. Typical approaches consist of acoustic cavitation, high energy planetary ball milling, reaction synthesis, and shock synthesis and modified spark plasma synthesis, followed by dynamic and static consolidation and densification pre and post reaction synthesis. Typical heterogeneous multiphase, multi microstructural constituent materials covered in this work consist of tungsten heavy alloys, coated graphite powders, metal silicide and aluminides and ceramic composites. The synthesized and densified materials were fully characterized by OM, SEM, TEM, EDX analysis, quantitative image analysis, X-Ray diffraction and mechanical testing. This paper presents and discusses the effect of reaction and processing parameters on the microstructure, densification, strength and toughness of typical heterogeneous materials and their application into the manufacture of advanced components and devices.

SESSION: AdvancedMaterialsSatPM1-R2	5th Intl. Symp. on New and Advanced Materials and Technologies for Energy, Environment and Sustainable Development
Sat Oct, 26 2019 / Room: Leda (99/Mezz. F)
Session Chairs: Gabor Patonay; Adriana Estokova; Session Monitor: TBA

15:15: [AdvancedMaterialsSatPM108] Keynote
Fabrication of High Entropy Alloys Shock Wave Consolidation of Ti-Ni-Fe-W-Cu Powders
Nikoloz Chikhradze¹ ; Fernand Marquis² ; Mikheil Chikhradze³ ; Guram Abashidze¹ ; Davit Tsverava⁴ ; ¹G. Tsulukidze Mining Institute, Tbilisi, Georgia; ²San Diego State University, San Diego, United States; ³Georgian Technical University, Tbilisi, Georgia; ⁴LEPL Grigol Tsulukidze Mining Institute/M.Sc. Student of Georgian Technical University, Tbilisi, Georgia;
Paper Id: 337 [Abstract]

High Entropy Alloys are characterized with specific properties, including high hardness, wear-resistance, high strength, structural stability, corrosion and oxidation-resistance [1-5]. The complex of desired properties defines the increasing interest for the application in different fields of engineering. In spite of the interest towards High Entropy Alloys/materials, most of the traditional methods do not allow the fabrication the desired varieties of composites due to the technological limitation. On the other hand, investigations towards high entropy materials are increasing as there are some properties that have to be studied and validated in multi-component systems. The goal of the current investigations is to carry out experiments and define synthesis regimes for Ti-Ni-Fe-W-Cu system powders by mechanical alloying and establish the technological parameters for the formation of High Entropy Alloys. The other goal of the work is to make experimental investigations for the synthesis of bulk materials by an explosive consolidation technique. The paper describes the preliminary theoretical investigations and initial experimental results of mechanical alloying and explosive compaction of the Ti-Ni-Fe-W-Cu multi-component system. As a result, the preliminary investigations establish the technological parameters for mechanical alloying. The blend with different percentages of content of powders was prepared. The high energetic planetary ball mill was used for blend processing, mechanical alloying, and amorphization ultrafine/nanopowder production. The time of processing varied in the range of 1-28 h. Selected Ball milled blends were compacted by explosive consolidation technology. For shock wave generation, the industrial explosives and new explosives obtained from decommissioned weapons were used in the experiments. The technological parameters of the explosive consolidation have been studied and are discussed in this 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