Synthesis of Si3N4 using Residual Organics Trapped in the Silica Gel by Sol-Gel Method

졸-겔법으로 제조된 실리카겔중의 잔류유기물을 이용한 $Si_3N_4$의 합성

  • 김병호 (고려대학교 공과대학 재료공학과) ;
  • 신현호 (고려대학교 공과대학 재료공학과) ;
  • 이재영 (고려대학교 공과대학 재료공학과)
  • Published : 1992.05.01

Abstract

Residual organics were considered as impurity in Sol-Gel method. The purpose of this study was to find the conditions to contain as much residual organics as possible in silica gel prepared from TEOS(tetraethylortho-silicate) by Sol-Gel method. Residual organics are to be expected to have reduction effect on synthesizing Si3N4 from silica gel. The results of this study are follows: 1) The maximum content of entrapped carbon was 19.8 wt.%(C/SiO2=0.25 wt.ratio) in silica gel synthesized under the conditions 1.5 fold mole water for incomplete hydrolysis, 2.5 fold mole phenol as a solvent and 0.1 fold mole HCl as a catalyst to TEOS. 2) Silica gel with organics entrapped by Sol-Gel method had a positive effect on the formation of Si3N4 compared with commercial silica gel. 3) Sintered body of synthesized $\alpha$-Si3N4 with Y2O3 and Al2O3 as additives at 175$0^{\circ}C$ in N2 atmosphere showed bending strength, 602$\pm$20 MPa and frature toughness 4.45$\pm$0.15 MPa.m1/2.

Keywords

References

  1. J. Mat. Sci. Lett v.10 no.7 Synthesis of the α form of Silicon Nitride from Silica K. Komeya;H. Inoue
  2. J. Am. Ceram. Soc. v.67 no.10 Preparation of Silicon Nitride from Silica Shi-Chang Zhang;W.R. Cannon
  3. J. Am. Ceram. Soc. Bull. v.57 no.6 Synthesis and Characterization of a Pure Silicon Nitride Powder Svante Prochazka;C. Grescovich
  4. J. Mat. Sci. v.22 Conversion of Precipitated Silica from Geothermal Water to Silicon Nitride D.S. Perera
  5. J. Am. Ceram. Soc. v.56 no.12 Synthesis, Characterization, and Consolidation of Si₃N₄obtained from Ammonlysis of SiCl₄ K.S. Mazdiyasni;C.M. Cooke
  6. J. Mat. Sci. v.20 The Influence of Iron on the Preparation of Silicon Nitride from Silica S.A. Siddiqi;A. Hendry
  7. SOL-GEL SCIENCE The Physics and Chemistry of Sol-Gel Processing C.J. Brinker;G.W. Scherer
  8. Ultrastructure Processing of Advanced Ceramics Various Factors Affecting the Conversion of Silicon Alkoxide solution to Gels Sumio Sakka;Hiromitsu Kozuka;Sae-hun Kim;John D. Mackenzie(ed.);Donald R. Ulich(ed.)
  9. J. Mat. Sci. v.12 Preparation of Glasses and Ceramics from Metalorganics Compounds B.E. Yoldas
  10. Ultrastructure Processing of Ceramics, Glasses and Composites Physical Chemical Factors in Sol-Gel Processing Michel Prassas;Larry, L. Hench
  11. J. Am. Ceram. Soc. v.59 Fracture Toughness Determinations by Indentation A.G. Evans;E.A. Charles
  12. The Aldrich Library of Infrared Spectra(Edition Ⅲ) Charles, J. Pouchert
  13. Elements of X-Ray Diffraction B.D. Cullity
  14. J. Am. Ceram. Soc. v.57 no.1 Hot-Pressing Behavior of Si₃N₄ G.R. Terwilliger;F.F. Lange
  15. J. Am. Ceram. Soc. v.56 no.12 Hot-pressed Si₃N₄ G.E. Gazza
  16. J. Mat. Sci v.21 Pressureless Sintering of Si₃N₄with Y₂O₃and Al₂O₃ T. Hayashy;H. Munakata
  17. J. Am. Ceram. Soc v.60 no.5-6 Phase Relation and Stability Studies in the Si₃N₄-SiO₂-Y₂O₃Pseudoternary System F.F. Lange;S.C. Singhal;R.C. Kuznicki
  18. J. Am. Ceram. Soc. v.56 no.10 Relation Between Strength, Fracture Energy, and Microstructure of Hot-pressed Si₃N₄ F.F. Lange