• Title/Summary/Keyword: Fiber shape

Search Result 840, Processing Time 0.038 seconds

Material Properties and Strengthening Mechanism in Shape Memory TiNi Fiber Reinforced Al Matrix composite (TiNi/Al 형상기억 지적복합재료의 기계적 특성 및 강화기구)

  • Park, Yeong-Cheol;Yun, Du-Pyo;Lee, Gyu-Chang;Huruya, Y.
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.21 no.3
    • /
    • pp.405-413
    • /
    • 1997
  • In the present paper, it is attempted to reconfirm the "Intelligent" material properties using both the sintered TiNi/Al(1100) matrix composite made by powder metallurgy method and the squeeze-casted TiNi/Al6061 specimens. A metal matrix composite is, its fault has been considered to deteriorate a strength of composite by heating residual stress of the matrix. Therefore, it is necessary to remove a tensile residual stress, to produce the strength of a composite better. On the contrary, if compressive residual stress happens in matrix of composite in place of tensile residual stress, it will make the strength of composite better. So that, this paper introduce the development of a high strength of composite, by using compressive residual stress well, on the study. By using these specimens, shape memory strengthening effects in tensile strength and fatigue crack propagation above inverse transformation temperature of TiNi fiber were investigated. We occurs the prestrain and volume fraction for to discuss the effects of a composite strength. Moreover, by SEM observation, the effect of the residual stress at the interface between Al matrix and TiNi fiber and some brittle precipitation layers such as inter metallic compounds on fracture mechanisms was discussed metallurgically.urgically.

Carbonization and Activation Behaviors of Metal Containing Carbon Fibers (금속함유 탄소섬유의 탄화 및 활성화 거동)

  • Young Ok CHOI;Kap Seung YANG
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.04a
    • /
    • pp.98-100
    • /
    • 2003
  • The efficiency of the adsorption of adsorbents depends on both pore size and shape. In other to adsorb hydrated ion in application of electric double layer capacitor (EDLC), mesopore is necessary[1,2]. Tamai et al.[3] reported that an increased portion of mesopore was introduced through addition of metal or organometallic compound in the precursor and following activation of the carbon fibers with steam. (omitted)

  • PDF

Synthesis and characterization of Star Shape Polycaprolactone containing 4-Arm Polycaprolactone Core (4개의 폴리카프로락톤 가지 코어를 가지는 스타형 폴리카프로락톤의 합성 및 분석)

  • An, Sung-Guk;Cho, Chang-Gi
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2002.04a
    • /
    • pp.199-202
    • /
    • 2002
  • The synthesis of materials with controlled composition and architectures continues to be a focus of considerable current research. Dendritic multiarm polymers such as dendrimer, hyperbranched polymer, and star polymers are three dimensional macromolecules, in which a large number of linear arms of similar molecular weight and narrow molecular weight distribution emanate from a central core. (omitted)

  • PDF

Hydroxyapatite/Chitosan Composites and its Application (Hydroxyapatite/키토산 복합재료 및 그 응용)

  • Chung, Yong-Sik
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2002.04a
    • /
    • pp.21-24
    • /
    • 2002
  • Hydroxyapatite(HAp, Ca$\sub$10/(PO$_4$)$\sub$6/(OH)$_2$, is a compound with structural and chemical resemblance bone mineral and of particular importance in the field of biomaterials. In addition to the non-toxicity and high compatibility with hard and soft tissue, HAp exhibits strong affinity to host hard tissues and protein molecules. However, HAP is difficult to shape in the specific forms due to its hardness and brittleness. (omitted)

  • PDF

A Study of the Formation Process of the Fabric Drapes

  • Mizutani, Chiyomi;Baba, Takeichirou;Amano, Toshihiko
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10a
    • /
    • pp.111-111
    • /
    • 2003
  • In our experiments using a new apparatus, the drape formation process was found to consist of three stages, seeds generation, their development and the final stabilizing stages. A new parameter R evaluating the shape of the drape was defined in terms of the vertical projection of the drape. Both drape coefficient and R-parameter are expected to be useful for analyzing the formation process of the fabric drape quantitatively.

  • PDF

Polyurethane-Carbon Nanotube Composites With Shape Memory Effect (형상기억 효과를 갖는 폴리우레탄-카본나노튜브 복합재료)

  • 김정원;정용채;조재환
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10b
    • /
    • pp.201-202
    • /
    • 2003
  • 탄소나노튜브는 역학적 물성이 뛰어날 뿐만 아니라 전기적 특성도 우수하여 현재 매우 많은 연구와 응용개발이 시도되고 있다 일반적으로 전기전도성 고분자 복합체를 얻기 위한 방법으로 카본블랙이나 전도성 섬유, 금속섬유, 전도성 분말 등을 고분자에 혼입하는 방법을 주로 이용하지만, 복합체 내에서 나노구조 형성이 가능한 탄소나노튜브를 이용하면 나노물질의 특성상 매우 유리한 점이 많다. 예를 들면, 우수한 전기특성, 낮은 임계농도, 우수한 역학적 성질 둥이다. (중략)

  • PDF

Preparation and Characterization of Shape Memory Polyurethane Nanofibers Using Electrospinning (전기방사를 이용한 형상기억 폴리우레탄 나노섬유의 제조 및 고찰)

  • 정용채;김정원;전병철;정용찬;윤영상;조재환
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10b
    • /
    • pp.255-256
    • /
    • 2003
  • 열가소성 폴리우레탄 공중합체는 가역적 변형을 갖는 soft segment와 물리적 가교역할을 하는 hard segment로 이루어져 있으며, 이들 두 segment domain의 상분리에 의하여 우수한 탄성효과를 발휘할 수 있으며 또한 적당한 구조제어에 의하여 형상기억효과를 나타내게 할 수 있다. 본 연구자들은 최근 형상기억 폴리우레탄 제조에 있어 soft segment의 배열을 달리함으로써 보다 우수한 역학적 성질을 갖는 시료를 얻을 수 있음을 보고하였다. (중략)

  • PDF

Preparation of composite laminate utilizing shape memory pohrethylene terephthalate-pohrethylene glycol copolymer (I) (형상기억능을 갖는 polyethylene terephthalate-polyethylene glycol 공중합체를 이용한 laminate 복합재료의 제조 (I))

  • 차상혁;박명주;정용찬;조재환;전병철
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2001.10a
    • /
    • pp.195-198
    • /
    • 2001
  • 최근 지능재료에 관한 연구가 형상기억합금, 반도체 재료, 의료용 재료, 고분자 재료 등에서 활발히 이루어지고 있다. 지능재료 중 형상기억재료는 형상기억, 형상고정, 충격흡수 등의 효과를 갖기 때문에 열적, 역학적, 전기적 및 자기적(magnetic) 자극을 감지함으로써 형상, 위치, 탄성계수, damping, 마찰 등의 특성변화를 통하여 응답을 할 수 있어 응용이 다양하다 형상기억고분자의 경우 가볍고 형상회복률이 높으며 가공성이 우수한 장점을 가지고 있다. (중략)

  • PDF

Effective Utilization of Hemp Fiber for Pulp and Papermaking (I) -Morphological Characteristics of Hemp Fiber- (펄프.제지용 원료로서의 삼 섬유 이용에 관한 연구(제 1보) -대마 구성 세포의 현미경적 관찰-)

  • Yoon, Seung-Lak;Lee, Myoung-Ku
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.42 no.1
    • /
    • pp.7-12
    • /
    • 2010
  • Morphological characteristics of hemp fiber were investigated using a light microscope in order to provide fundamental data for the use of hemp as a papermaking law material. Phloem of hemp is composed of cortical parenchyma cells and bast fiber with thick walls while xylem is composed of vessel, wood fiber and ray parenchyma cells. Also there are solitary pore and radial pore multiple which exist in diffuse porous pattern. Ray cells consist of uniseriate rays and thin walled ray parenchyma cells. Wood fibers are composed of three types: a large diameter fiber with longer length; a large diameter fiber with shorter length; a small diameter fiber with medium length. Vessel elements are composed of: a medium length one; a longer length one; the one whose both end walls have ligules or tails. Parenchyma cells in xylem and pit parenchyma cells have completely different size and shape. For bast fiber, the average length is about 4.4 mm and the width is about $30.5\;{\mu}m$; for vessel element, $600.0\;{\mu}m$ in length and $493.6\;{\mu}m$ in width; for wood fiber, $1000\;{\mu}m$ and $38.9\;{\mu}m$; for parenchyma cell, $50\;{\mu}m$ and $26.4\;{\mu}m$.