• Title/Summary/Keyword: Metallic Materials

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Microscopic analysis of metal matrix composites containing carbon Nanomaterials

  • Daeyoung Kim;Hye Jung Chang;Hyunjoo Choi
    • Applied Microscopy
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    • v.50
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    • pp.4.1-4.10
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    • 2020
  • Metallic matrix composites reinforced with carbon nanomaterials continue to attract interest because of their excellent mechanical, thermal, and electrical properties. However, two critical issues have limited their commercialization. Uniform distribution of carbon nanomaterials in metallic matrices is difficult, and the interfaces between the nanomaterials and matrices are weak. Microscope-based analysis was recently used to quantitatively examine these microstructural features and investigate their contributions to the composites' mechanical, thermal, and electrical properties. The impacts of the microstructure on these properties are discussed in the first section of this review. In the second section, the various microscopic techniques used to study the distribution of carbon nanomaterials in metallic matrices and their interfaces are described.

Removal and Separation of Metallic Constituents from the By-product Recovered from Gold Mine Tailings (금(金) 광산(鑛山) 폐광미(廢鑛尾)로부터 회수(回收)된 금속광물(金屬鑛物) 부산물(副産物) 중의 금속성분(金屬成分) 분리(分離), 제거연구(除去硏究))

  • Youn, Ki-Byoung
    • Resources Recycling
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    • v.19 no.3
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    • pp.9-15
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    • 2010
  • Domestic gold mine tailings, generally, contain a lot of non-metallic silica and clay minerals. These minerals can be separated from the tailings by various physical separation methods and used as raw materials for cements and ceramic products. In these physical separation procedures, metallic complex sulfides, in which Au and metallic constituents such as Pb, As and Fe were concentrated, were obtained as a by-product. These metallic constituents should be removed or separated from the by-product to extract Au efficiently. In this work, removal and separation processes of Pb, As, and Fe from the by-product were investigated. Pb was removed to under 3% by using alkaline oxidative leaching at the leaching condition of $120^{\circ}C$, 2M NaOH, 100psi $Po_2$, 250r.p.m., 4 wt.% solid and 30 min. leaching time. The leached residue was roasted and separated magnetically to obtain a non-magnetic product contained <0.2% As, <3% Fe and high concentrated Au more than 8,000 ppm.

Improvement on resolution of mono-filament wire (초음파 팬텀 내 모노필라멘트의 해상력 개선에 대한 연구)

  • Ma, Sang-Chull;Kong, Young-Kun
    • Journal of radiological science and technology
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    • v.26 no.2
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    • pp.49-56
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    • 2003
  • The purposes of this study are to improve the ultrasound resolution of various nylon and metallic mono-filament wires, therefore, it was tested that it analyze on nylon mono-filament wire of 0.1 mm in A Co.'s ultrasonic phantom and synthesis of C15 g tissue mimicking materials(TMM), analyze resolution of nylon and metallic mono-filament wires in water and TMM. The results obtained were summarized as follows: 1. Metallic mono-filament wire of 0.1 mm and nylon mono-filament wire of 0.12 mm, 180 denier showed that it cleared dot echo pattern. 2. Metallic and nylon mono-filament wire of 0.2 mm showed that it cleared comet tail echo by reverberation artifact. 3. Nylon and metallic mono-filament wire of 0.1 mm showed that it can used for dead zone and axial resolution test. 4. Nylon mono-filament wire compared with metallic mono-filament wire showed that it satisfy elasticity and construction. 5. Degree of hardness of na not changed mono-filament's echo textures.

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Mechanical Properties of a Cu55Zr30Ti10Pd5 Bulk Amorphous Alloy (Cu55Zr30Ti10Pd5 비정질 합금의 기계적 거동)

  • Choi Won Wook;Gato H.;Kim Hyoung Seop;Hong Sun Ig;Inoue A.
    • Korean Journal of Materials Research
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    • v.15 no.4
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    • pp.281-284
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    • 2005
  • Room and high temperature deformation behaviors of Cu-Zr-Ti-Pd bulk metallic glasses produced by copper mold casting were investigated. The addition of Pd was shown to enhance the glass forming ability and thermal stability of Cu-Zr-Ti base bulk metallic glass. The compressive strength of $Cu_{55}Zr_{30}Ti_{10}Pd_5$ bulk metallic glass was 2230 MPa with 1.8 plastic strain. The stress overshoot and yield drop phenomenon were observed below $487^{\circ}C$ and a drastic decrease in the flow stress was observed at $487^{\circ}C$. The stress overshoot is thought to be associated with stress-induced structural relaxation.

Structural Assessment of the Optimal Section Shape of FRP Based Stiffeners (FRP 보강재의 최적 단면 형상 결정 및 평가에 관한 연구)

  • Jeong, Han-Koo;Nho, In-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.5
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    • pp.435-444
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    • 2011
  • This paper deals with the structural assessment of metallic and non-metallic stiffened/monocoque plated marine structures under a lateral pressure load to identify appropriate combination of material and section configuration, especially at the preliminary marine structural design stage. A generic rectangular plated structure is exemplified from the metallic superstructure of a marine vessel and its structural topology is varied for the structural assessment. In total 13 different structural topologies are proposed and assessed using appropriate elastic solutions in conjunction with a set of stress and deflection limits obtained from practice. The geometry dimensions and weights of the structural topologies are calculated, and subsequently, the costs of the materials used in the structural topologies are reviewed to discuss the cost-effectiveness of the materials. Finally, conclusions are made with the aim of suggesting suitable structural topology for the marine structural member considered in this paper.

A Composite of Metal and Polymer Films: Thin Nickel Film Coated on a Polypropylene Film after Atmospheric Plasma Induced Surface Modification

  • Song, Ho-Shik;Choi, Jin-Moon;Kim, Tae-Wan
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.3
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    • pp.110-114
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    • 2011
  • Polymeric films of high chemical stability and mechanical strength covered with a thin metallic film have been extensively used in various fields as electric and electronic materials. In this study, we have chosen polypropylene (PP) as the polymer due to its outstanding chemical resistance and good creep resistance. We coated thin nickel film on PP films by the electroless plating process. The surfaces of PP films were pre-treated and modified to increase the adhesion strength of metal layer on PP films, prior to the plating process, by an environment-friendly process with atmospheric plasma generated using dielectric barrier discharges in air. The surface morphologies of the PP films were observed before and after the surface modification process using a scanning electron microscope (SEM). The static contact angles were measured with deionized water droplets. The cross-sectional images of the PP films coated with thin metal film were taken with SEM to see the combined state between metallic and PP films. The adhesion strength of the metallic thin films on the PP films was confirmed by the thermal shock test and the cross-cutting and peel test. In conclusion, we made a composite material of metallic and polymeric films of high adhesion strength.

The Formative Aesthetic of Paco Rabanne's Works with Material (Paco Rabanne의 특수소재를 이용한 작품의 발상과 조형미)

  • Kim, Jee-Yeon;Lee, Kyoung-Hee
    • Fashion & Textile Research Journal
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    • v.4 no.4
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    • pp.317-326
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    • 2002
  • This study is to analyze the works introduced in the collections of Paco Rabanne in an aim to identify formative aesthetic and design concepts. As the data to study the creative concepts and expressions of the designer, fashion photographs were gathered in a focus on collections. Paco Rabanne's fashion philosophy is to shine women who has passion, energy and self-confidence, with glittering materials. For he had a career of fashion accessary designer and architect, he tried to make his work constructively with non-sewing technology. So, his works could be divided three parts of materials which he has made creative fashion with. They are metallic, non-metallic and fabric. In metallic, design concepts are cosmos, egypt, the middle ages, modern technology. And from these the formative aesthetic were mainly characterized by the futurism, cubism and eroticism. In non-metallic, building, purism of primitiveness, nature. And from these the formative aesthetic were mainly characterized by surrealism, primitivism, romantism. In fabric, design concepts are natural phenomena, optical illusion. And from these the formative aesthetic were mainly characterized by cubism, optical art.