• 제목/요약/키워드: SEM images

검색결과 628건 처리시간 0.031초

Quantitative analysis of retained austenite in Nb added Fe-based alloy

  • Kwang Kyu Ko;Jin Ho Jang;Saurabh Tiwari;Hyo Ju Bae;Hyo Kyung Sung;Jung Gi Kim;Jae Bok Seol
    • Applied Microscopy
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    • 제52권
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    • pp.5.1-5.10
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    • 2022
  • The use of Pipelines for long-distance transportation of crude oil, natural gas and similar applications is increasing and has pivotal importance in recent times. High specific strength plays a crucial role in improving transport efficiency through increased pressure and improved laying efficiency through reduced diameter and weight of line pipes. TRIP-based high-strength and high-ductility alloys comprise a mixture of ferrite, bainite, and retained austenite that provide excellent mechanical properties such as dimensional stability, fatigue strength, and impact toughness. This study performs microstructure analysis using both Nital etching and LePera etching methods. At the time of Nital etching, it is difficult to distinctly observe second phase. However, using LePera etching conditions it is possible to distinctly measure the M/A phase and ferrite matrix. The fraction measurement was done using OM and SEM images which give similar results for the average volume fraction of the phases. Although it is possible to distinguish the M/A phase from the SEM image of the sample subjected to LePera etching. However, using Nital etching is nearly impossible. Nital etching is good at specific phase analysis than LePera etching when using SEM images.

3차원 X-ray 단층 화상을 이용한 스카른 광석의 정량분석 연구 (Quantitative Analysis of Skarn Ore Using 3D Images of X-ray Computed Tomography)

  • 정미희;조상호;정수복;김영훈;박재구
    • 한국광물학회지
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    • 제23권3호
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    • pp.211-217
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    • 2010
  • 스카른 Zn-Pb-Cu 복합광석을 구성하는 주요 구성 광물의 정량분석을 목적으로, 마이크로 포커스 X-ray 단층촬영 장비를 이용한 스카른 복합광석의 3차원 비파괴검사를 수행하였다. X-ray 단층화상의 화상결함을 감소시키고자 제안된 화상보정법을 이용하여 화상들을 보정한 후에 3차원으로 재구성하였다. 주사전자현미경(SEM)에 의한 표면분석과 보정된 X-ray 단층화상을 비교하여 주요광물에 대한 CT 값의 범위를 결정하였다. 재구성화상 내 전체 광물의 체적비율을 분석한 결과, 황화광물 20.5%, 맥석광물 79.5%로 평가되었다. X-ray 3차원 단층화상 정량분석법은 광석 내 유용광물의 부존형상과 회수율 분석에 유용하게 적용될 것으로 기대된다.

고배율 도공층 구조 및 S/B latex 분포 분석을 위한 도공층 횡단면 제작 (Preparation of Cross-sectional Specimen for High Resolution Observation of Coating Structure and Visualization of Styrene/butadiene Latex Binder)

  • 김채훈;윤혜정;이학래
    • 펄프종이기술
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    • 제44권4호
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    • pp.16-24
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    • 2012
  • To characterize the coating structure, diverse methods such as mercury intrusion, nitrogen adsorption and oil absorption methods have been developed and widely employed. These indirect techniques, however, have some limitation to explain the actual coating structure. Recently microscopic observation methods have been tried for analyzing structural characteristics of coating layers. Preparation of the undamaged cross section of a coating layer is essential for obtaining high quality image for analysis. In this study, distortion-free cross-section of the coating layer was prepared using a grinding and polishing technique. The coated paper was embedded in epoxy resin and cured. After curing the resin block it was ground with abrasive papers and then polished with diamond particle suspension and nylon cloth. Polished coating layer was sufficient enough to obtain undamaged cross sectional images with scanning electron microscope under backscattered electron image mode. In addition, the SEM images allowed distinction of the coating layer components. Also S/B latex film formed between pigment particles was visualized by osmium tetroxide staining. Pore size distribution and pore orientation were evaluated by image analysis from SEM cross-sectional images.

Surface properties of Nb oxide thin films prepared by rf sputtering

  • 박주연;강용철
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.306.2-306.2
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    • 2016
  • Niobium oxide thin films were synthesized by reactive rf magnetron sputtering. The target was metallic niobium with 2 inch in diameter and the substrate was n-type Si wafer. To control the surface properties of the films, Nb oxide thin films were obtained at various mixing ratios of argon and oxygen gases. Nb oxide thin films were analyzed with alpha step, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The result of alpha step showed that the thickness of Nb oxide thin films were decreased with increasing the oxygen gas ratios. SEM images showed that the granular morphology was formed at 0% of oxygen gas ratio and then disappeared at 20 and 75% of oxygen gas ratio. The amorphous Nb oxide was observed by XRD at all films. The oxidation state of Nb and O were studied with high resolution Ni 2p and O 1s XPS spectra. And the change in the chemical environment of Nb oxide thin films was investigated by XPS with Ar+ sputtering.

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후처리 조건에 따른 탄소나노튜브 특성의 변화 (Study of Carbon Nanotubes Properties by Post-treatment Conditions)

  • 최성헌;이재형;양종석;박대희;허정구
    • 한국전기전자재료학회논문지
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    • 제19권10호
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    • pp.930-934
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    • 2006
  • This paper reports a change of carbon nanotubes(CNTs) properties by post-treatment process after growth of CNTs. CNTs were treated by thermal method and solution method, and then investigated in detail using field emission scanning electron microscopy(FE-SEM), high resolution transmission scanning electron microscopy(HR-TEM), RAMAN spectroscopy, and Fourier Transform Infrared Spectrometer (FT-IR). FT-IR spectra showed that the amount of hydroxyl generated on surface of CNTs were changed with post-treatment condition. FE-SEM and TEM images were shown CNTs diameter and density variations were dependent with their treatment conditions. RAMAN spectroscopy was shown that carbon nanotubes structure vary with treatment conditions.

주사전자현미경용 전자검출기 (The Electron Detector in Scanning Electron Microscope)

  • 이상욱;전종업;한상훈
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.513-517
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    • 2004
  • The nature of the signals collected by an SEM(Scanning Electron Microscope) in order to form images are all dependent on the detector used to collect them, and the quality of an acquired image is strongly influenced by detector performance. Therefore, the development of detector with high performance is very important in pulling up the resolution of SEM. In this article, electron beam-specimen interactions, the detection principle of secondary electrons and backscattered electrons, and the structure of a conventional detector are described. The structure of an experimental apparatus for the future study on our hopeful novel electron detector is presented as well.

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UV-Induced Graft Polymerization of Polypropylene-g-glycidyl methacrylate Membrane in the Vapor Phase

  • Hwang, Taek-Sung;Park, Jin-Won
    • Macromolecular Research
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    • 제11권6호
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    • pp.495-500
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    • 2003
  • UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

Photografting of PET Fabrics with Vinyl Pyrrolidone and Acryloyl Morpholine Monomers

  • Huang, Weiwei;Jang, Jin-Ho
    • 한국염색가공학회지
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    • 제20권5호
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    • pp.28-34
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    • 2008
  • PET fabrics were photografted under continuous UV irradiation with vinyl pyrrolidone (VP) and acryloylmorpholine(ACMO) as monomers and benzophenone as a hydrogen-abstractable photoinitiator. ACMO can be grafted onto the PET fabrics more efficiently than VP. The grafted PET surfaces were characterized by ATR, ESCA, SEM and zeta potential measurement. ATR and ESCA analysis indicated significant alterations on chemical structure and atomic composition on the surface of the grafted fabrics, where nitrogen content increased with increasing grafting yield. SEM images showed that the fabric surface was covered with the grafted polymers. The zeta potentials and the water wettability of the grafted PET increased with grafting. Also the photografted fabrics showed an increased dyeablity to reactive dyes and increased affinity to various iodine species which imparted anti-bacterial properties.

새로운 방식에 외해 제작된 $TiO_2$ 박막의 나노입자크기(IV) (Nanoparticle Size of $TiO_2$ Thin-Films Fabricated by Novel Method(IV))

  • 문정오;정재훈;김강언;문병기;손세모;정수태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.760-763
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    • 2002
  • Nanoparticle size of Titanium dioxide thin films was prepared by novel method. Particle size and surface structure of $TiO_2$ thin films were investigated by atomic force microscopy(AFM), scanning electron microscopy(SEM). All thin films process were prepared at room temperature. Particle size was reduced from 100 to 30nm with increasing amount of $Ti[OCH(CH_3)_2]_4$ observed by AFM images. All thin films were irradiated for 5 minutes by white light. Increasing the annealing temperature, particles size was increased. In the $TiO_2$(40%) thin films was annealed at $300^{\circ}C$ for 30minutes, the particle size was about 10nm.

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목련잎 추출액을 이용한 자성 나노입자의 합성 (Synthesis of Magnetic Nanoparticles Using Magnolia kobus Leaf Extract)

  • 송재용;변태강;김범수
    • KSBB Journal
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    • 제27권3호
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    • pp.157-160
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    • 2012
  • When iron oxide magnetic nanoparticles were synthesized by co-precipitation method using aqueous ammonia as reducing agent, the synthesized particles were aggregated and thus precipitation occurred. Using Magnolia kobus leaf extract as reducing agent, spherical nanoparticles of 50~200 nm were synthesized with low yield. By using both Magnolia kobus leaf extract and aqueous ammonia as reducing and stabilizing agents, smaller nanoparticles of 40~120 nm could be synthesized with various shapes. The synthesized magnetic nanoparticles were characterized with field emission transmission electron microscopy (FE-TEM) and scanning electron microscopy (SEM). TEM and SEM images showed that the magnetic nanoparticles are a mixture of triangles, tetragons, rods and spherical structures.