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Clarification of Liquid Phase Sintering Process of Silicon Nitride from the Perspective of Physico-Chemical Properties of High Temperature Melts

Research Project

Project/Area Number 16360376
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Metal making engineering
Research InstitutionKYUSHU UNIVERSITY

Principal Investigator

NAKASHIMA Kunihiko  KYUSHU UNIVERSITY, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (10207764)

Co-Investigator(Kenkyū-buntansha) KANEKO Kenji  KYUSHU UNIVERSITY, Graduate School of Engineering, Associate Professor, 大学院・工学研究院, 助教授 (30336002)
Project Period (FY) 2004 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 2005: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 2004: ¥9,800,000 (Direct Cost: ¥9,800,000)
Keywordssilicon nitride / anisotropic grain growth / rare-earth oxide / physico-chemical properties / elevated temperature melts
Research Abstract

The effect of RE_2O_3 (RE=Y,Gd,Nd and La) on the viscosity and the surface tension of 45.2MgO-54.8SiO_2 (mol%) melts have been investigated with rotating crucible viscometer and ring method, respectively. Additionally, structural characterizations of these quenched vitreous samples have been investigated with Infra-Red spectrometer.
The viscosities of RE_2O_3-MgO-SiO_2 melts were found to decrease with increasing the content of any rare-earth additions, which suggests that rare-earth oxide behaves as a network modifier of complex silicate anions in high temperature melts. The viscosities decreased in the order of cationic radius of rare-earth ; from Y_2O_3,Gd_2O_3,Nd_2O_3 to La_2O_3. The surface tension of MgO-SiO_2 binary melts were found to increase with increasing the content of any rare-earth additions. The surface tensions obviously increased in the order of cationic radius of rare-earth, which the change of with rare-earth addition is direct antithesis of that of viscosities.
Isoth … More ermal growth of (β-Si_3N_4 crystals dispersed in a series of rare-earth (RE=Y,Gd,Nd and La) oxynitride liquids (RE-Mg-Si-O-N) was studied after heat treatment at 1773 K for 64 to 512 min. The microstructural characterization of α-_and β-Si_3N_4 crystals was quantitatively analyzed by electron microscopy. The volume fraction of (β-Si_3N_4 crystals in oxynitride glasses increased with heat treatment time. It is determined that the rate of α/β transformation in the oxynitride liquid with Y_2O_3 additive can be faster than that in oxynitride liquids with other additives. Likewise, the radii of rare-earth elements make significant differences in the mean grain size and aspect ratio of β-Si_3N_4 crystals. In all cases mentioned above, a marked change was observed in the order of ionic radius from La to Y. The mean width of the needlelike β-Si_3N_4 crystals heat-treated with La_2O_3 additive was almost constant in the time range of heat treatment in this study. However, the aspect ratio of β-Si_3N_4 crystals with La_2O_3 additive was found to be much larger than that in oxynitride liquids with other additives, indicating negligible growth of β-prism plane. Less

Report

(3 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • Research Products

    (9 results)

All 2006 2005

All Journal Article (9 results)

  • [Journal Article] Viscosity and Surface Tension Measurements of RE_2O_3-MgO-SiO_2(RE=Y, Gd, Nd and La) Melts2006

    • Author(s)
      FumiyamiSHIMIZU et al.
    • Journal Title

      ISIJ International 46

      Pages: 388-393

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Viscosity and Surface Tension Measurements of RE_2O_3-MgO-SiO_2 (RE=Y,Gd,Nd and La) Melts2006

    • Author(s)
      Fumiyuki SHIMIZU et al.
    • Journal Title

      ISIJ International Vol.46

      Pages: 388-393

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Viscosity and Surface Tension Measurements of RE_2O_3-MgO-SiO_2(RE=Y,Gd,Nd and La) Melts2006

    • Author(s)
      Fumiyumi SHIMIZU et al.
    • Journal Title

      ISIJ International 46

      Pages: 388-393

    • Related Report
      2005 Annual Research Report
  • [Journal Article] MgO-SiO_2系融体の液相線温度および粘度に及ぼすRE_2O_3(RE=Y, Gd, Nd and La)添加の影響2005

    • Author(s)
      齊藤敬高ら
    • Journal Title

      日本金属学会誌 69

      Pages: 152-158

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] RE(RE=Y, Gd, Nd and La)-Mg-Si-O-N系融体中におけるβー窒化ケイ素の結晶成長2005

    • Author(s)
      中田大司ら
    • Journal Title

      日本金属学会誌 69

      Pages: 719-722

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Effect of RE_2O_3 (RE=Y,Gd,Nd and La) Additions on Liquidus Temperatures and Viscosities of MgO-SiO_2 Melts2005

    • Author(s)
      Noritaka SAITO et al.
    • Journal Title

      Journal of Japan Institute of Metals Vol.69

      Pages: 152-158

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Grain Growth of β-Silicon Nitride in RE (RE=Y,Gd,Nd and La)-Mg-Si-O-N Melts2005

    • Author(s)
      Daiji NAKATA et al.
    • Journal Title

      Journal of Japan Institute of Metals Vol.69

      Pages: 719-722

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] MgO-SiO_2系融体の液相線温度および粘度に及ぼすRE_2O_3(RE=Y,Gd,Nd and La)添加の影響2005

    • Author(s)
      齊藤敬高ら
    • Journal Title

      日本金属学会誌 69

      Pages: 152-158

    • Related Report
      2005 Annual Research Report
  • [Journal Article] RE(RE=Y,Gd,Nd and La)-Mg-Si-O-N系融体中におけるβ-窒化ケイ素の結晶成長2005

    • Author(s)
      中田大司ら
    • Journal Title

      日本金属学会誌 69

      Pages: 719-722

    • Related Report
      2005 Annual Research Report

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Published: 2004-04-01   Modified: 2016-04-21  

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