• 제목/요약/키워드: Composite powders

검색결과 580건 처리시간 0.032초

분말야금공정으로 제조한 SiCw/6061Al 복합재료의 미세조직에 미치는 ECAP가공의 영향 (Effect of ECAP on Microstructure of SiCw/6061Al Composites Produced by Powder Metallurgy)

  • 장시영
    • 한국분말재료학회지
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    • 제9권1호
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    • pp.11-18
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    • 2002
  • The 6061 Al alloy based composites reinforced with 10 vol% SiC whiskers were prepared by powder metallurgy with the powders having the different sizes, i.e. < $30{\mu}m$ and > $30{\mu}m$ The composites were subjected to equal channel angular pressing (ECAP) at various conditions and the microstructural changes during ECAP were examined In the composites SiC whiskers were clustered and randomly aligned. The clusters were relatively well distributed in the composite with the smaller initial powder size. After ECAP, the clusters were aligned parallel to flow direction and became smaller. In addition, the shape of clusters was changed from irregular to round. The microstructure of the ECAPed samples were compared with those of the conventionally hot-extruded composites. The uniform microstructure and enhanced microhardness could be obtained by using the powders having the smaller size, decreasing ECAP temperature and repeating ECAP.

Cu기 벌크 비정질 복합체의 성형 및 특성 (Consolidation and Characterization of Cu-based Bulk Metallic Glass Composites)

  • 이진규;김택수
    • 한국분말재료학회지
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    • 제14권6호
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    • pp.399-404
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    • 2007
  • The Cu-based bulk metallic glass (BMG) composite was fabricated by spark plasma sintering (SPS) using of gas-atomized metallic glass powders and ductile brass powders. No defect such as pores and cavities was observed at the interface between the brass powder and the metallic glass matrix, suggesting that the SPS process caused a severe viscous flow of the metallic glass and brass phases in the supercooled liquid region, resulting in a full densification. The BMG composites shows some macroscopic plasticity after yielding, although the levels of strength decreased.

Effect of Powder Synthesis Processing on the Microstructure and Electrical Conductivity of Sintered $CNTs/Fe/Al_2O_3$ Nanocomposites

  • Choa, Yong-Ho;Yoo, Seung-Hwa;Yang, Jae-Kyo;Park, Jin-Woo;Oh, Sung-Tag;Kang, Kae-Myung;Kang, Sung-Goon
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1087-1088
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    • 2006
  • The microstructure and electrical conductivity of CNTs dispersed $Al_2O_3$ nanocomposites depending on the powder processing and CNTs content were demonstrated. The composite powders with homogeneous dispersion of CNTs could be synthesized by a catalytic route for direct formation of CNTs on nano-sized Fe dispersed $Al_2O_3$ powders. The sintered nanocomposite using the composite powder with directly synthesized CNTs showed homogeneous microstructure and enhanced elelctrical conductivity. The influence of powder processing on the properties of sintered nanocomposites was discussed by the observed microstructural features.

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구조물 미세크랙 예측용 CPGFRP센서 개발 (Development of CPGFRP Sensor for Fine Crack Detection of Structures)

  • 신순기;장창우;박윤한;김승언;김황수;이준희
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.119-122
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    • 2004
  • A CPGFRP(Carbon Powder Glass Fiber Reinforced Plastics) sensor was fabricated for fine crack detection of structures. The electrical resistance of the sensor was measured on condition of various composition of carbon powders and thickness of bundle of glass fibers. The resistance was decreased as the increase of the content of carbon powders and the TEX of the glass fibers. In the case of loading on CPGFRP sensor, because inner crack was propagated, the part of percolation structures was disconnected. The sensor is superior to carbon fiber for the detecting ability of fine crack.

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Dry Coated Particle for Plasma Spraying

  • Briones-Rodriguez, C.;Mayagoitia-Barragan, V.;Cuenca-Alvarez, R
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.156-157
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    • 2006
  • The preparation of composite powders for plasma spraying by an in-house designed mechanofusion process is investigated. Results show that dry particle coating depends on the chemical and mechanical properties of powders. In metal/oxide and metal/oxide/carbide powder mixtures, fine ceramic particles coat the surface of the metallic coarser particles. A nearly rounded shape of the final composite particles is induced by the mechanical energy input with no formation of new phases. However with the carbide/metal powdered system, only an intimate mixture of components is achieved. It is suggested that the coating mechanism is governed by agglomeration and rolling phenomena.

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Discrete Element Simulation of the Sintering of Composite Powders

  • Martina, C. L.;Olmos, L.;Schneiderb, L. C. R.;Bouvardc, D.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.262-263
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    • 2006
  • The free sintering of metallic powders blended with non sintering inclusions is investigated by the Discrete Element Method (DEM). Each particle, whatever its nature (metallic or inclusion) is modeled as a sphere that interacts with its neighbors. We investigate the retarding effect of the inclusions on the sintering kinetics. Also, we present a simple coarsening model for the metallic particles, which allows large particles to grow at the expense of the smallest.

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