• 제목/요약/키워드: Materials characterization

검색결과 2,929건 처리시간 0.038초

철계 복합 분말로 제조된 오버레이 용접층의 미세조직 및 특성 (Microstructure and Characterization of Overlay Welding Layer using Fe-based Composite Powders)

  • 민홍;이종재;이진규
    • 한국분말재료학회지
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    • 제26권3호
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    • pp.214-219
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    • 2019
  • In this study, the microstructure and characterization of an overlay welding layer using Fe-based composite powders are reported. The effects of the number of passes and composition of powders on the microstructure and mechanical properties are investigated in detail. The welding wire and powders are deposited twice on a stainless-steel rod using a laser overlay welding process. The microstructure and structural characterization are performed by scanning electron microscopy and X-ray diffraction. The mechanical properties of the first and second overlay layers are analyzed through the micro-Vickers-hardness tester and abrasion wear tester. In the second overlay layer, the hardness and specific wear are approximately 840 Hv and $2.0{\times}10^{-5}mm^3/Nm$, respectively. It is suggested that the increase of the volume fractions of $(Cr,Fe)_7C_3$ and NbC phases in the second welding layer enhances the hardness and wear resistance.

Antimicrobial Evaluation and Characterization of Copper Nanoparticles Synthesized by the Simple Chemical Method

  • Wazir, Arshad Hussain;Khan, Qudratullah;Ahmad, Nisar;Ullah, Faizan;Quereshi, Imdadullah;Ali, Hazrat
    • 한국재료학회지
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    • 제32권2호
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    • pp.80-84
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    • 2022
  • Copper nanoparticles (CuNPs) are considered of great importance due to their high catalytic and antimicrobial activities. This study focuses on the preparation and characterization of CuNPs, and on their antibacterial/antifungal activities. A copper salt (copper sulfate pentahydrate) as precursor, starch as stabilizing agent, and ascorbic acid as reducing agent were used to fabricate CuNPs. The resulting product was characterized via different techniques such as X-ray diffractrometry (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning electron microscopy (SEM) to confirm its characteristic properties. Employing the Scherrer formula, the mean crystallite sizes of copper (Cu) and cuprous oxide (Cu2O) nanocrystals were found to be 29.21 and 25.33 nm, respectively, as measured from the main X-ray diffraction peaks. The functional groups present in the resulting CuNPs were confirmed by FTIR. In addition, the engineered CuNPs showed antibacterial and antifungal activity against tested pathogenic bacterial and fungal strains.

Spectroscopic characterization of electroluminescent ZnS:Cu,Cl phosphor coated by sol-gel process

  • Lee, You-Hui;Han, Chi-Hwan;Han, Sang-Do;Chang, Mi-Youn;Sharma, Gaytri.;Park, Youn-Bong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1323-1326
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    • 2005
  • The photoluminescence, electroluminescence and surface properties of ZnS:Cu,Cl phosphor coated by sol-gel process were studies. Na-silicate was used as precursor coating material. pH of solution and the concentration of Na-silicate are the important conditions to obtain the uniform coating on the phosphors. Also, the electroluminescent devices were made with Na-silicate coated phosphor. The spectroscopic characterization is performed by photospectrometer.

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Characterization of the mechanical behavior of PEKK polymer and C/PEKK composite materials for aeronautical applications below and above the glass transition temperature

  • Pedoto, Giuseppe;Smerdova, Olga;Grandidier, Jean-Claude;Gigliotti, Marco;Vinet, Alain
    • Advances in aircraft and spacecraft science
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    • 제7권6호
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    • pp.475-493
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    • 2020
  • This paper is focused on the characterization of the thermomechanical properties of semicrystalline poly-ether-ether-ketone (PEKK) and of carbon fiberreinforced thermoplastic based laminated composites (C/PEKK) below and above the glass transition temperature (Tg). Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) and tensile tests are carried out on both pure PEKK polymer and [(±45)2, +45]s C/PEKK composite samples, showing a significant similarity in behavior. The employment of a simple micromechanical model confirms that the mechanical and physical behavior of the polymer and that of the matrix in the composite are similar.

ISO/TC 108/WG 28 : Characterization of the Dynamic Mechanical Properties of Resilient Visco-Elastic Materials 활동상황보고 (ISO/TC 108/WG 28 : Characterization of the Dynamic Mechanical Properties of Resilient Visco-Elastic Materials)

  • 김광준
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.799-810
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    • 2001
  • 필자는 소음진동공학회가 품질기술원으로부터 ISO/TC108 기계진동 및 충격(Mechanical Vibration and Shock) 간사기관업무를 위탁 받은 후부터 SC6 진동 및 충격 발생시스템(Vibration and Shock Generating Systems)에 대한 한국측 위원으로 일을 해왔다. (중략)

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Atom Probe Tomography: A Characterization Method for Three-dimensional Elemental Mapping at the Atomic Scale

  • Choi, Pyuck-Pa;Povstugar, Ivan
    • 한국분말재료학회지
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    • 제19권1호
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    • pp.67-71
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    • 2012
  • The present paper gives an overview about the Atom Probe Tomography technique and its application to powder materials. The preparation of needle-shaped Atom Probe specimens from a single powder particle using focused-ion-beam milling is described. Selected experimental data on mechanically alloyed (and sintered) powder materials are presented, giving insight into the atomic-scale elemental redistribution occurring under powder metallurgical processing.