• Title/Summary/Keyword: whisker

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Synthesis and characterization of potassium titanate whisker by flux method (융제법을 이용한 티탄산칼륨 휘스커의 합성과 특성)

  • Choi, Yeon-Bin;Son, Jeong-hun;Bae, Dong Sik
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.4
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    • pp.150-154
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    • 2016

  • Method for synthesizing a $K_2Ti_6O_{13}$ whisker is a solid-state method, hydrothermal synthesis method, calcination method, flux method, slow-cooling method, melting method, kneading-drying-calcination method, sol-gel method etc. $K_2Ti_6O_{13}$ whisker have been synthesized by a flux method. The average size and distribution of the synthesized $K_2Ti_6O_{13}$ whisker can be controlled by a kind of potassium precursors and reaction temperature and time. The average size of the synthesized $K_2Ti_6O_{13}$ whisker was about in the size range of 500 nm to $2{\mu}m$. The effect of synthesis parameters, such as the molar ratio of KOH to $TiO_2$, pH, reaction temperature and time, are discussed. The synthesized $K_2Ti_6O_{13}$ whisker were characterized by x-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM).

  • https://doi.org/10.6111/JKCGCT.2016.26.4.150 인용 PDF KSCI

Synthesis of Silicon Carbide Whiskers (I) : Reaction Mechanism and Rate-Controlling Reaction (탄화규소 휘스커의 합성(I) : 반응기구의 율속반응)

  • 최헌진;이준근
    • Journal of the Korean Ceramic Society
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    • v.35 no.12
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    • pp.1336-1336
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    • 1998

  • A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

Structure and Growth of Tin Whisker on Leadframe with Lead-free Solder Finish (무연솔더 도금된 리드프레임에서 Sn 위스커의 성장과 구조)

  • Kim Kyung-Seob;Leem Young-Min;Yu Chong-Hee
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.3 s.32
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    • pp.1-7
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    • 2004

  • Tin plating on component finishes may grow whiskers under certain conditions, which may cause failures in electronics equipment. To protect the environment, 'lead-free' among component finishes is being promoted worldwide. This paper presents the evaluation results of whiskers on two kinds of lead-free plating materials at the plating temperature and under the reliability test. The rising plating temperature caused increasing the size of plating grain and shorting the growth of whisker. The whisker was grown under the temperature cycling the bent type in matt Sn plating and striated type in malt Sn-Bi. The whisker growth in Sn-Bi plating was shorter than that in Sn plating. In FeNi42 leadframe, the $7.0{\~}10.0{\mu}m$ diameter and the $25.0{\~}45.0{\mu}m$ long whisker was grown under 300 cycles. In the 300 cycles of Cu leadframe, only the nodule(nuclear state) grew on the surface, and in the 600 cycles, a $3.0{\~}4.0{\mu}m$ short whisker grew. After 600 cycles, the ${\~}0.34{\mu}m$ thin $Ni_3Sn_4$ formed on the Sn-plated FeNi42. However, we observed the amount of $0.76{\~}1.14{\mu}m$ thick $Cu_6Sn_5$ and ${\~}0.27{\mu}m$ thin $Cu_3Sn$ intermetallics were observed between the Sn and Cu interfaces. Therefore, the main growth factor of a whisker is the intermetallic compound in the Cu leadframe, and the coefficient of thermal expansion mismatch in FeNi42.

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기능성 카본계 막의 개발과 수처리 응용에의 검토에 관한 연구

  • Bae, Sang-Dae
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2006.05a
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    • pp.431-434
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    • 2006

  • 폴리머 라텍스의 탄화와 메탄-질소 혼합가스의 CVD법으로 Carbon whisker를 가진 활성탄막을 개발하였다. 이 막의 PMMA 현탁물질 여과실험과 실제의 현탁물질과 용존유기물을 함유한 오래된 수도관으로부터 얻어진 적수여과실험 결과, Carbon whisker의 유무가 fouling에 의한 막의 flux를 억제하는 것으로 밝혀져, 실제의 정수공정에의 응용 가능성을 보였다.

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