• Title/Summary/Keyword: compositional change

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

  • 김지순;양석균;정순호;강지훈;권영순
    • Journal of Powder Materials
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    • v.11 no.1
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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
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.1
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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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Analysis of Thermodynamic Conditions for Formation of Single Phase in Bi-superconductor Thin Films (Bi 초전도 박막에서 단일상 형성을 위한 열역학 조건 분석)

  • Ahn, Joon-Ho;Park, Yong-Pill;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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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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Thermal and Mechanical Characteristics of Functionally Graded ZrO$_2$ Thermal Spray Coating (경사기능성 지르코니아 용사피복층의 열 및 기계적특성)

  • 오동현
    • Journal of the Korean institute of surface engineering
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    • v.31 no.2
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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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Analysis of Thermodynamics for Formation of Single Phase in Bi-superconducting Thin Films (Bi 초전도 박막에서 단일상 형성을 위한 열역학 분석)

  • 천민우;박용필
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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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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Analysis of Thermodynamic Conditions for Formation of Single Phase in Bi-superconductor Thin Films (Bi 초전도 박막에서 단일상 형성을 위한 열역학 초건 분석)

  • 안준호;박용필;김정호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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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
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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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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Transformation of the enthalpy and the entropy in BSCCO:2212-2223 (BSCCO:2212-2223 박막의 엔탈피와 엔트로피 변화)

  • Cheon, Min-Woo;Park, No-Bong;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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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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Effect of Compositional Ratio of Additives on the Plating Properties in Environment-Friendly Electroless Plating Reaction (친환경 무전해 도금반응에서 첨가제의 조성비가 도금특성에 미치는 영향)

  • Chun, Kyung-Soo;Paik, Gwi-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.4015-4021
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    • 2011
  • The purpose of this study is to investigate the effect of compositional ratio of additives, such as potassium ferrocyanide, aminoacetic acid (=glycine) and 2,2'-dipyridyl, on the physical properties of copper layer deposited by environment-friendly electroless plating reaction. The highest plating rate of copper layer, $9.5mg{\cdot}cm^{-2}{\cdot}hr^{-1}$, was obtained at 20 mg/L of potassium ferrocyanide and 0.01 mol/L of aminoacetic acid, which coincided with the change in the hardness of the copper layer. In the additives used in this study, potassium ferrocyanide was considered to improve the plating rate, aminoacetic acid increased the hardness value of deposited films and 2,2'-dipyridyl enhanced the brightness of copper deposited films.

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

  • Kim Kun-Ki;Kim Jong-Sun;Jwa Yong-Joo
    • The Journal of the Petrological Society of Korea
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    • v.14 no.1
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    • pp.12-23
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    • 2005
  • Cretaceous granitic rocks in the Waryongsan area occur as a stock and show compositional changes with altitude. They include mafic microgranular enclaves (MME) with various sizes and types. The MMEs present clear evidence of magma mingling such as supercooling zone, mantling texture and back veining. The granitic rocks are divided into porphyritic granite, porphyritic granodiorite and fined-grained granite by their petrographic characteristics and modal compositions. The MMEs are discriminated to quartzdioritie, quartzmonzodiorite and tonalite. They have varying areal proportions in each granitic rock-type: 10∼l5% in the porphyritic granite, about 50% in the porphyritic granodiorite, and about 20% in the fined-grained granite. SiO₂ contents shows compositional change of 61.2∼72.0wt.%. Mean SiO₂ contents have 61.7wt.% in the porphyritic granodiorite, 68.6wt.% in the porphyritic granite. and 71.9wt.% in the fined-grained granite, respectively. Major oxide contents of the granitic rocks linearly vary with SiO₂ contents from the porphyiritic granodiorite to the fine-grained granite on Harker diagrams. Linear compositional variations seem to have been caused by differential degrees of mingling between mafic magma and host granite. Where larger amount of mafic magma was injected into the host granitic magma, the two magmas reached to thermal equilibrium more quickly and eventually chemical mixing occurred to produce the composition of the porphyritic granodiorite. On the other hand. less amount of injected mafic magma would have been responsible for mechanical mixing to produce the compositions of the porphyritic granite and the fined-grained granite. Therefore, it is considered that the granitic rocks in the Waryongsan area experienced magmas mingling resulting from the injection of more mafic magma into differentiating granitic magma, and that the compositional changes of the granitic rocks were ascribed to the degree of mingling between the two magmas.