• Title/Summary/Keyword: SiC Whisker

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A Study on the Fatigue Strength Evaluation of Metal Matrix Composite (금속기 복합재료의 피로강도 평가에 관한 연구)

  • 김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.2
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    • pp.41-53
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    • 1994
  • In this paper, rotating-bending fatigue tests of the SiC-whisker- reinforced 6061-T6 aluminum alloy and 6061-T6 alumiunm alloy made by power metallurgy were carried out to investigate the fatigue characteristics of plain and notched specimens at room temperature. The fatigue mechnisms in both materials were clarified through successive surface observations using the plastic replica method. In the case of the SiC-whisker-reinforced composites, there are whisker rich and poor zones and the fatigue crack is nucleated from the end of whiskers near the boundary. On the other hand, in the case of the 6061-T6 aluminum alloy, the fatigue crack is nucleated from defects and propagates by shear. Moreover, the results were discussed based on linear notch mechanics.

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Improvement of Mechanical and Interfacial Properties of Carbon Fiber/Epoxy Composites by Adding Nano SiC Fillers (나노 SiC 입자의 형상에 따른 탄소섬유 강화 에폭시 복합재료의 기계적 및 계면 물성 변화 관찰)

  • Kwon, Dong-Jun;Wang, Zuo-Jia;Kim, Je-Jun;Jang, Key-Wook;Park, Joung-Man
    • Journal of Adhesion and Interface
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    • v.14 no.2
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    • pp.75-81
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    • 2013
  • Epoxy matrix based composites were fabricated by adding SiC nano fillers. The interfacial properties of composites were varied with different shapes of SiC nano fillers. To investigate the shape effects on the interfacial properties, beta and whisker type SiC nano fillers were used for this evaluation. The dispersion states of nano SiC-epoxy nanocomposites were evaluated by capacitance measurements. FE-SEM was used to observe the fracture surface of different structures of SiC-epoxy nanocomposites and to investigate for reinforcement effect. Interfacial properties between carbon fiber and SiC-epoxy nanocomposites were also evaluated by ILSS (interlaminar shear strength) and IFSS (interfacial shear strength) tests. The interfacial adhesion of beta type nanocomposites was better than whisker type.

On the study of $AlSiCa(Al_2O_3-SiC-C)$ refractories: (II) Oxidation and sintering of the synthesized powders ($AlSiCa(Al_2O_3-SiC-C)$계 내화물 재료에 관한 연구:(II) 합성원료의 산화 및 소결 특성)

  • Shim, Kwang-Bo;Joo, Kyoung;Auh, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.481-486
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    • 1997
  • It was succeeded in synthesizing the $Al_2O_3$-SiC refractory powders, which is main raw material of AlSiCa, from the domestic Hadong Kaolin. The oxidation reaction of the synthesized $Al_2O_3$-SiC powder was examined. The activation energy for SiC in $Al_2O_3$-SiC powder was calculated to be $\Delta$G=74.86 KJ/mol in air, however the poor sinterability of the powders is thought to be due to the vaporization of SiC in $H_2$ atmosphere. The formation of the whisker-SiC gives the possibility in use for high temperature structural material over high temperature refractory brick.

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Synthesis of Mullite Whiskers by Vapor-Solid Reaction in the System of Al(OH)3-SiO2-AlF3 (Al(OH)3-SiO2-AlF3계에서 기상-고상반응에 의한 뮬라이트 휘스커 합성)

  • Lee, Hong-Lim;Kang, Jong-Bong
    • Journal of the Korean Ceramic Society
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    • v.43 no.6 s.289
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    • pp.376-382
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    • 2006
  • In the $Al(OH)_3-SiO_2-AlF_3$ system, leaf-shaped fluorotopaz was first formed at $800^{\circ}C$ and mullite whisker was formed at $1,100^{\circ}C$. The mass transportation of Al and Si as gas phase, the fast reaction and growth, and the absence of liquid phase existence in mullite whisker showed that the formation and growth of mullite was from the solid-vapor reaction.

A Study on Residual Stress of SiC Whisker Reiforced AI Alloy/$ZrO_2$ Joints (SiC 휘스커강화 금속복합재료와 지르코니아 접합체의 잔류응력 해석에 관한 연구)

  • 주재황;박명균
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.18-26
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    • 1996
  • A two dimensional thermo elasto-plastic finite element stress analysis was performed to study residual stress distributions in AI composites reinforced by SiC whisker and $ZrO_2$ ceramic joints. The influences on the residual stress distributions due to the difference of the reinforcement volume fraction and interlayer material property were investigated. Specifically, stress distributions between AI interlayer material property were investigated. Specifically, stress distributions between AI interlayer and $ZrO_2$ ceramic and between the AI interlayer and AI composite were computationally analzed.

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Effects of Titania Whisker Precipitation on Wear Property of the Glass-Ceramic (타이타니아 단섬유상의 석출이 결정화유리의 마모특성에 미치는 영향)

  • 이경호
    • Journal of the Korean Ceramic Society
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    • v.33 no.2
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    • pp.192-202
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    • 1996
  • In Li0.4Ca0.05AlP0.5Si0.75O4.5 composition glass, glass-ceramic having a near 100% crystallinity after nucleation heat treatment of 74$0^{\circ}C$/2 h and crystallization heat treatment of 90$0^{\circ}C$/2 h and in-situ TiO2 whisker reinforced glass-ceramic after heat treatment of 105$0^{\circ}C$ for 20 h were fabricated with the addition of 4% TiO2 as a nucleating agent. With these materials a ball-on-disc type wear test was conducted in order to examine the effect of TiO2 whisker prepcipitation on ambient and high temperature wear properties of the glass-ceramic. Wear test results indicated that all specimens exhibited micro-fracture wear mechanism in ambient temperature. As temperature increased the wear rates of the materials were increased. However the in-situ TiO2 whisker reinforced glass-ceramic exhibited the lowest wear rate over the test temperature range. This resulted from the improvement of harness and fracture toughness of the material as the glass converted into the glass-ceramic followed by precipitation of TiO2 whiskers throughout the glass-ceramic matrix.

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