• 제목/요약/키워드: Collodal Particle

검색결과 2건 처리시간 0.014초

고부피분율 SiC분말 예비성형체의 제조공정과 기계적특성 (Fabrication Process and Mechanical Properties of High Volume Fraction SiC Particle Preform)

  • 전경윤
    • 한국분말재료학회지
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    • 제7권1호
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    • pp.27-34
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    • 2000
  • The fabrication process and mechanical properties of SiC particle prefrrms with high volume fraction ranged 50∼71% were investigated to make metal matrix composites for possible applications as heat sinks in electronic packares. The SiC particle preforms with 50∼71vol% of reinforcement were fabricated by a new modified process named ball milling and pressing method. The SiC particle performs were fabricated by ball milling of SiC particles with single sized of 48${\mu}$m in diameter or two different size of 8${\mu}$m and 48${\mu}$min diameter, with collodal SiO2 as inorgnic binder in distilled water, and the mixed slurries were cold pressed for consolidation into final prefom. The compressive strengths og calcined SiC particle prefoms increased from 20MPa to 155MPa with increasing the content of inorganis binder, temperature and time for calcination. The increase of compressive strength of SiC particle bridge the interfaces of two neighboring SiC particles.

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Fabrication and Optical Characterization of Colloidal 3-D Photonic Crystals

  • N. Y. Ha;Y. Woo;Park, Byungchoo;J. W. Wu
    • 한국진공학회지
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    • 제12권S1호
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    • pp.15-16
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    • 2003
  • 3-D photonic band-gap structures are fabricated from dielectric colloidal polystyrene beads through a centrifuge method. The fabricated photonic crystals exhibit opalescent colors under white light and show a clear diffraction peak dependent on the incident angle of the light beam. Also the scanning electron microscope image was taken to verify the face-centered cubic crystal structure. Bragg's law and Snell's law are employed to describe the position of angle resolved diffraction peaks. It was shown that the optically deduced effective refractive index and lattice constants were in good agreement with the crystal structure identified by scanning electron microscope.