• 제목/요약/키워드: compositional change

검색결과 153건 처리시간 0.023초

방전플라즈마소결에 있어서의 (Ti+Ni) 혼합불말의 소결거동 (Sintering Behavior of (Ti+Ni) Powder Mixture during Spark-Plasma Sintering)

  • 김지순;양석균;정순호;강지훈;권영순
    • 한국분말재료학회지
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    • 제11권1호
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    • pp.55-59
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    • 2004
  • TiNi bodies were produced from (Ti+Ni) powder mixture by spark-plasma sintering procerg. The sintering behavior was investigated through the measurement of change in density, densification rate, phase analysis and microstructure. Irrespective of heating rate, sintered bodies with above 97% relative density could be obtained. TiNi with B2 structure was confirmed as the major phase and $Ti_2Ni,\;TiNi_3$, unreacted Ti, Ni as the second phase. Increase in heating rate suppressed a formation of intermediate phase during sintering process. Increase in holding time at sintering temperature led to a compositional homogenization.

Thermodynamics for Formation of Each Stable Single Phase in Bi-superconductor Thin Films

  • Park, Yong-Pil;Kim, Gwi-Yeol
    • 한국전기전자재료학회논문지
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    • 제14권1호
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    • pp.64-68
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    • 2001
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\_$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO phases appeared against T$\_$sub/ and PO$_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable phases depending on T$\_$sub/ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

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Bi 초전도 박막에서 단일상 형성을 위한 열역학 조건 분석 (Analysis of Thermodynamic Conditions for Formation of Single Phase in Bi-superconductor Thin Films)

  • 안준호;박용필;김정호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.304-307
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    • 2001
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $PO_3$. The correlation diagrams of the BSCCO phases appeared against $T_{sub}$ and $PO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi220l and Bi2223 phases as well as Bi2212 one come out as stable phases depending on $T_{sub}$ and $PO_3$. From these results, the thermodynamic evaluations of ${\Delta}H$ and ${\Delta}S$ S, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

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경사기능성 지르코니아 용사피복층의 열 및 기계적특성 (Thermal and Mechanical Characteristics of Functionally Graded ZrO$_2$ Thermal Spray Coating)

  • 오동현
    • 한국표면공학회지
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    • 제31권2호
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    • pp.91-100
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    • 1998
  • NiCrAlY/YSZ(8wt%$Y_2O_3-ZrO_2$) functionally graded thermal barrier coating (FGC) layers on a Co-base superalloy (HAYNESS 188) substrate were fabstrate were fabicated using Ar shielded single torch air plasma spraying method. Functional grading with the stepwise compositional change throughout layer thickness. Microstructural observation trvealed a successful fabrication of NiCrAlY/YSZ FGC. From the results of the curvature measurement, adhesive strength measurement and thermal shock test for the FGC, it was concluded that the optimum conditions of functionally graded coating layer thinkness and compositional pattern exit to enhance the properties of FGC, which is closely related to the internal residual stess distribution witin it.

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Bi 초전도 박막에서 단일상 형성을 위한 열역학 분석 (Analysis of Thermodynamics for Formation of Single Phase in Bi-superconducting Thin Films)

  • 천민우;박용필
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2002년도 춘계종합학술대회
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    • pp.623-626
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    • 2002
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, Tsub, and ozone gas pressures, pO$_3$. The correlation diagrams of the BSCCO phases with Tsub and pO$_3$are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputterina Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on Tsub and pO$_3$. From these results, the thermodynamic evaluation of ΔH and ΔS, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

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Bi 초전도 박막에서 단일상 형성을 위한 열역학 초건 분석 (Analysis of Thermodynamic Conditions for Formation of Single Phase in Bi-superconductor Thin Films)

  • 안준호;박용필;김정호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.304-307
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    • 2001
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\sub$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO Phases appeared against T7ub and PO3 are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable Phases depending on T$\sub$sub/ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

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Thermodynamics for Formation of Each Stable Single Phase in BSCCO Thin Films

  • Yang, Sung-Ho;Park, Yong-Pil;Kim, Gwi-Yeol
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.104-107
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    • 2000
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$\_$sub/, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO Phases appeared against T$\_$sub/ and PO$_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable phases depending on T$\_$sub/ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase are performed.

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BSCCO:2212-2223 박막의 엔탈피와 엔트로피 변화 (Transformation of the enthalpy and the entropy in BSCCO:2212-2223)

  • 천민우;박노봉;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.589-590
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    • 2005
  • BSCCO:2212-2223 thin films were fabricated by using the ion beam sputter with a evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the BSCCO phases with Tsub and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on Tsub and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

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친환경 무전해 도금반응에서 첨가제의 조성비가 도금특성에 미치는 영향 (Effect of Compositional Ratio of Additives on the Plating Properties in Environment-Friendly Electroless Plating Reaction)

  • 전경수;백귀찬
    • 한국산학기술학회논문지
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    • 제12권9호
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    • pp.4015-4021
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    • 2011
  • 시아나이드 화합물과 같은 환경에 유해한 도금첨가제를 사용하지 않는 친환경적인 무전해 구리도금용 도금용액조성을 개발하기 위하여, potassium ferrocyanide, aminoacetic acid (=glycine), 2,2'-dipyridyl과 같은 첨가제를 이용하여 첨가제의 투입량 또는 조성비가 도금특성에 미치는 영향을 조사하였다. 무전해도금으로 적층된 구리도금층의 도금속도는 potassium ferrocyanide와 aminoacetic acid의 조성비가 20 mg/L과 0.01 mol/L 이었을 때, $9.5mg{\cdot}cm^{-2}{\cdot}hr^{-1}$으로 나타났으며, 도금경도의 변화도 도금속도와 연동하여 비례적으로 변화하였다. 하지만 potassium ferrocyanide를 첨가하지 않은 도금용액의 조성에서도 $9.1mmg{\cdot}cm^{-2}{\cdot}hr^{-1}$의 도금속도를 나타내었다.

경상분지 남서부 와룡산 일대에 분포하는 백악기 화강암류에 관한 암석학적 연구: 마그마 불균질 혼합에 의한 화강암류의 조성변화 (Petrological Study of Cretaceous Granitic Recks in the Waryongsan Area, Southwestern Gyeongsang Basin: Compositional Change of Granitic Rocks by Magma Mingling)

  • 김건기;김종선;좌용주
    • 암석학회지
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    • 제14권1호
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    • pp.12-23
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    • 2005
  • 와룡산 일대에 암주상으로 분포하는 백악기 화강암류는 고도에 따른 수직적인 조성변화를 보인다. 이들 화강암류 내에는 다양한 크기와 형태의 염기성 미립 포유암들이 산출되며, 과냉각대, 망토조직, 그리고 벡베이닝 등과 같은 마그마 혼합의 뚜렷한 증거들이 나타난다. 화강암류는 암석기재적 특징과 모드분석결과로부터 반상화강암, 반상화강섬록암, 그리고 세립질화강암으로 세분되며, 염기성 미립 포유암은 석영섬록암, 석영몬조섬록암, 그리고 토날라이트 조성을 가진다. 화강암류 내에 염기성 미립 포유암의 분포 면적비는 반상화강암이 10∼15%, 세립질화강암이 약 20%, 그리고 반상화강섬록암이 약 50% 정도로 반상화강섬록암에 집중되어 분포한다. 화강암류 주성분 원소 분석결과를 하커변화도에 도시해 보면 반상화강섬록암에서 세립질화강암으로 가면서 선적인 변화경향을 보이며, SiO₂ 함량은 61.2∼72.0wt.%의 조성변화를 보이며, 반상화강섬록암은 평균 61.7wt.%, 반상화강암은 평균 68.6wt.%, 그리고 세립질화강암은 71.9wt.%의 조성을 가진다. 이와 같은 조성의 변화는 마그마 불균질 혼합에 의한 것으로 매픽 마그마의 양적인 비율에 따른 혼합 정도의 차이에 기인하는 것으로 생각된다. 매픽 마그마의 양이 많은 부분에서는 열적 평형에 빨리 도달하여 화학적 혼합에 의한 반상화강섬록암의 조성이 우세하고, 매픽 마그마의 양이 적은 부분은 기계적인 혼합에 의한 반상화강암과 세립질화강암의 조성이 우세한 것으로 고찰할 수 있다. 따라서 와룡산 일대 화강암류는 화강암질 마그마가 어느 정도 결정분화된 단계에서 보다 매픽한 마그마의 주입으로 인해 마그마 불균질 혼합이 발생하게 되었으며, 혼합된 두 마그마의 양적인 비율에 의해 화강암류의 조성이 변화된 것으로 판단된다.