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Late News Poster Session: Nanostructured Materials
Program Organizers: TMS Administration

Monday 5:30 PM
February 28, 2022
Room: Exhibit Hall C
Location: Anaheim Convention Center

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NOW ON-DEMAND ONLY - H-28: Carbon Nanotubes Reinforced WC-Co Hard Alloys: Guolong Tan¹; Chenglong Li²; Xijun Wu³; ¹Wuhan University of Technology ; ²Nostan Comapny; ³Zhejiang University
    A novel approach for the synthesis of carbon nanotubes strengthened nanostructured WC-Co hard alloys will be presented. Nanometer sized tungsten and cobalt powders were fabricated by reduction process and then carburized by C2H2 instead of CO, while a small fraction of decomposed carbons were in situ converted into carbon nanotubes. The composite WC-Co powders were subsequently hot pressed into bulk alloys, which show exceptionally high Vickers microhardness up to 3307 kg/mm2. The carbon nanotubes with exceptionally high Young's Modules plays a key role on improving the mechanical properties of WC-Co matrix alloys through dispersion strengthening effect. Recently, this technique has been scaled up in a startup company termed as Nostan Company, the Vickers microhardness of these pilot produced alloys reaches 3508 kg/mm2,the highest hardness value in the world. The flexural strength is higher than 2200MPa. The products could now be made in much larger size up to (dia)50×5mm.

H-29: Enhancing HER Performance of Transition Metal Borides (TMBs) Nanoparticles Synthesized with Excess Sn Flux: Sang Bum Kim¹; Boniface Fokwa¹; ¹University of California, Riverside
     Transition metal borides (TMBs) are known for their: low-cost, high activity, stability in both acidic and basic electrolytes in hydrogen evolution reaction (HER). Furthermore, nanoscale TMBs would have a larger surface area, thus showing an increased number of active sites, and leading to higher catalytic performance. This was proven in a recent study where TMB nanoparticles, synthesized by Sn flux, showed significantly higher catalytic activity than their bulk counterparts, despite their high aggregation. It remains a challenge to synthesize highly dispersed TMB nanoparticles.In this study, the effect of excess Sn in TMB nanosynthesis is analyzed. Excessive flux in the synthesis is correlated to an increased reaction rate, thus enabling milder reaction conditions, such as lower temperature and shorter reaction time. With the experimental modifications of Sn amount and reaction conditions, its effects on the size, aggregation, and HER catalytic activity of the produced TMB nanoparticles were studied.

H-30: Evidence for Nanoindentation Induced Dynamical Recovery in Aluminum: Yuwei Zhang¹; George Pharr¹; ¹Texas A&M University
    In this study, we performed nanoindentation on pure aluminum samples with various indentation depth. With the help of FIB lift out and STEM detector in SEM, we found subgrain forming underneath the indents which display different orientation than the parent crystal form. This observation implies that the variation of hardness with increase of indentation depth is not only related with dislocation nucleation and multiplication, but that the polygonization of dislocations which would turn into low angle grain boundaries exhibits significant influence on the indentation hardness as well. This work highlights the importance of scrutinizing the microstructural evolution in understanding the plastic deformation of materials at nano-micro scale.

H-31: Evolution of Microstructure and Crystallographic Texture of Ni-Mn-Ga Melt-spun Ribbons Exhibiting 1.15% Magnetic Field-induced Strain: Anna Wojcik¹; Robert Chulist¹; Maciej Kowalczyk²; Przemyslaw Zackiewicz³; Pawel Czaja¹; Norbert Schell⁴; Wojciech Maziarz¹; ¹Institute of Metallurgy and Materials Science PAS; ²The Faculty of Materials Science and Engineering, Warsaw University of Technology; ³Lukasiewicz Research Network—Institute of Non-Ferrous Metals; ⁴Institute of Materials Physics, Helmholtz-Zentrum Geesthacht
     The microstructure and texture evolution of Ni-Mn-Ga melt-spun ribbons were investigated by high-energy synchrotron radiation and electron backscatter diffraction. The as-spun ribbons were thermally treated in order to optimize microstructure, atomic order degree, and crystallographic texture influencing on the functional properties. The optimum annealing treatment at 1173 K for 72 h allowed to produce a homogenous <100> fiber texture with the grain size spanning the entire ribbon thickness. A homogenous radial microstructure ensured in-plane stress/strain compatibility, which gives rise to strain accommodation during variant reorientation. Special attention was also given to the evaluation of atomic order, which mainly controls the characteristic transformation temperatures and reduces the twinning stress to a level sufficiently low for martensitic variant reorientation under magnetic field. As a result, 1.15% magnetic field-induced strain in the self-accommodated state was achieved.National Centre for Research and Development (NCBiR) of Poland is acknowledged for funding (TECHMATSTRATEG 2/410941/4/NCBR/2019).

Cancelled
H-32: Fabrication of NiFe(CO3)(OH)2 Composite Nano-sheet Arrays for Supercapacitor: Kyung Mox Cho¹; Kwang Ho Kim¹; ¹Pusan National University
     This paper reports the production of 3D binary NiFe(CO3)(OH)2 composites as a positive electrode on Ni-foam using a facile hydrothermal method. The NiFe(CO3)(OH)2 composites obtained in this manner exhibited a nano-sheet structure. This structure led to a high conductivity for the electrode, which facilitated an easier electrolyte reaction with the electrode. This helps achieve high electrochemical properties. A 3D open structure composed of a NiFe(CO3)(OH)2 composite was grown directly on porous nickel-foam using an effective one-step hydrothermal method. In addition, as the content of Fe increased, the electrochemical properties were improved, which is because the shape of the nano-sheets of the NiFe(CO3)(OH)2 composites become thinner and more uniform. As a result, the good electrochemical characteristics of the NiFe(CO3)(OH)2 composite electrode make it a promising positive material for highperformance supercapacitor applications

Cancelled
H-33: Hydrothermally Processed Ni(OH)2 Nano-sheet Electrode for Supercapacitor: Kyung Mox Cho¹; Kwang Ho Kim¹; ¹Pusan National University
    Binder-free Ni(OH)2 nano-sheet electrodes on Ni-foam were fabricated using a facile hydrothermal method using an etching process for high-performance supercapacitor applications. Ni(OH)2 nano-sheet have been studied extensively as a positive electrode material in supercapacitors The nanostructure of Ni(OH)2 can supply a higher specific surface area that enhances the electrode/electrolyte contact site remarkably. This paper presents uniquely designed Ni(OH)2 nano-sheet arrays on Ni-foam, which were different from the previously reported Ni(OH)2 materials that grew on Ni-foam. A mesoporous Ni(OH)2 nano-sheet electrode was grown directly on the 3D Ni-foam by a hydrothermal method using the etching process for high-performance supercapacitors. The Ni(OH)2 electrode after this etching process has a large specific surface area, which can increase the interface area of the electrode/electrolyte and shorten the ion diffusion path. These surface properties highlight the potential of the electrode in supercapacitors as well as in various industrial aspects

H-34: Low-cost Solution Processed Facile h-MoO3 Synthesis for Heterojunction Diode: Surendra Kumar¹; Kamal Rudra²; Abhishek Kumar Singh³; Sanjai Singh¹; Pramod Kumar¹; ¹Indian Institute of Information Technology-Allahabad; ²University of Michigan; ³Rajiv Gandhi Institute of Petroleum Technology
    In recent times, heterojunctions of 1-D nanorods of transition metal oxides with n-type silicon have shown some peculiar electrical properties. Owing to such peculiarities, we investigate the electrical behavior of n-Si heterojunction with chemically synthesized h-MoO3 nanorods. To fabricate heterojunction, first, the nanorods were ground and suspended in a solution of ethanol and DI water followed by sonication in a water bath for 2 hours and centrifugation at 4000 rpm. The supernatants were collected. FESEM and XRD confirm the formation of h-MoO3 nanorods. Optical properties were characterized using UV-Visible spectroscopy. The collected supernatants were deposited over n-type silicon by spin coating at 1500 rpm for 15 seconds followed by the aluminium contact deposition. Room temperature current-voltage (IV) measurements of the heterojunction show a rectifying behavior with a rectification ratio of ̴12. This facile fabrication process paves the way for various low-cost applications especially in the field of sensing and photonics.

H-35: Microscratch Characterization of Multilayered Cu-Nb Produced by Accumulative Roll Bonding: Hamed Zeinalabedini¹; Sezer Ozerinc¹; ¹Middle East Technical University
    Multilayered metals are a promising class of materials with outstanding strength, thermal stability, and irradiation resistance. Accumulative roll bonding (ARB) is the primary method for the synthesis of multilayered metals in bulk form for structural applications. Cu-Nb is among the most widely studied systems for understanding the structure-property relationships in ARB-produced multilayers. However, there has been no systematic work characterizing the wear performance of Cu-Nb multilayers. In this work, we microscratch tested multilayered Cu-Nb to understand the mechanical response under sliding wear. Cu-Nb laminates with layer thicknesses down to submicron scale have been produced by ARB. SEM, XRD, and microhardness measurements characterized the microstructure and mechanical properties. Microscratch testing and analyses of the wear tracks showed that the wear resistance dramatically increases as the layer thickness goes down to the submicron level. The findings provide key information towards the use of nanolayered metallic alloys in applications involving sliding contact conditions.

NOW ON-DEMAND ONLY - H-36: Multiferroism of La Modified M-type Hexaferrites: Guolong Tan¹; Congcong Duan²; Nan Nan²; ¹Wuhan University of Technology ; ²Wuhan University of Technology
    Ferroelectric polarization and magnetic properties in La modified M-type hexaferrites (LaMFe12O19) will be presented, together with antiferroelectric characterization of heavily doped ferrites. The remnant polarization of the LaMFe12O19 ceramic changes from around 100 μC/cm2 down to 0 when La content varies from 0 up to 0.6, exhibiting large pure double hysteresis loops at room temperature. The phase transition peak for ferroelectrics to antiferroelectrics moves from 450C down to -126C in the temperature-dependent dielectric constant spectrum, leaving a wide space for the stay of full antiferroelectric phase at the vicinity of room temperature. The heavily rare earth doped hexaferrites display strong magnetodielectric effect with change ratio of 540% in dielectric cosntant as well as GMR effect upon a magnetic field of 1.1T. Strong ferromagnetic semiconducting performance was observed in this compound. The combination of antiferroelectricity and ferromagnetism provides us an opportunity to fabricate novel multiferroic memories and energy storage devices.

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