Hot-Pressing of Silicon Nitride Containing Low Amounts of $Y_2O_3$ and AlN

Y2O3-AlN 미량첨가 질화규소의 열간가압소결

  • 조덕호 (명지대학교 무기재료공학과) ;
  • 이형복 (명지대학교 무기재료공학과)
  • Published : 1992.02.01

Abstract

Partially stabilized alpha-sialon composition (X=0.1) powder was hot-pressed at 1800~200$0^{\circ}C$ for 0~90 min with 30 MPa. Sintering behavior, phase changes and mechanical properties for the specimens were studied. As sintering temperature was raised from 1800 to 190$0^{\circ}C$, the relative density tended to increase and reached 99% of theoretical at 190$0^{\circ}C$. However the amount of alpha-sialon decreased because alpha-sialon transformed to beta-Si3N4 and yttrium rich silicate glass. In the case of hot-pressing at 190$0^{\circ}C$ for various times, densification increased with sintering time and full densification above 99% of theoretical was attained by 30 min. The amount of alpha-sialon decreased with sintering time. The maximum strength of 825 MPa was obtained by hot-pressing at 190$0^{\circ}C$ for 60 min.

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References

  1. J. Am. Ceram. Soc. v.64 no.2 Preparation of High-Density Si₃N₄by a Gas-Pressure Sintering Process C. Greskovich
  2. ibid v.57 no.2 High Temperature Strength Behavior of Hot-Pressed S₃N₄ : Evidence for Subcritical Crack Growth F.F. Lange
  3. Yogyo-Kyokai-Shi v.95 no.2 HIP Sintering of Silicon Nitride without Additives K. Homma;H. Okada;T. Fujikawa;T. Tatsuno
  4. J. Am. Ceram Soc. v.65 no.4 Strengthening of Sintered Silicon Nitride by Post-Fabrication Heat Treatment D.R. Clarke;F.F. Lange;G.D. Schmittgrund
  5. ibid v.58 Effect of Crystallizing the Grain Boundary Glass Phase on the High-Temperature Strength of Hot-Pressed Si₃N₄Containing Y₂O₃ A. Tsuge;K. Nishida;M. Komatsu
  6. Nitrogen Ceramics Crystal Chemistry of SiAlONs and Related Nitrogen Ceramics K.H. Jack;F.L. Riley. Noordhoff(ed.)
  7. J. Mater Sci. v.19 Rietveld Refinements for Calcium and Yttrum Containing a-Sialons F. Izumi;M. Mitomo;Y. Bando
  8. Verlag Deutsche Keramische Gesellschaft Some Properties of a-Sialon Ceramics K. Ishizawa;N. Ayuzawa;A. Shiranita;M. Takai;N. Uchida;M. Mitomo
  9. J Am. Ceram Soc. v.59 Fracture Toughness Determination by Indentation A.G. Evans;E.A. Charles
  10. Am. Ceram. Soc. Bull v.56 no.9 Determination of Phase Content of Si₄N₄ by X-ray Diffraction Analysis C.P. Gazzara;D.R. Meesier
  11. Yogyo-Kyokai-shi v.94 no.1 Pressureless Sintering of Si₃N₄with CeO₂Y₂O₃and Al₂O₃ H. Suzuki;H. Saito
  12. ibid v.89 no.4 Densification and Phase Transformation of Si₃N₄by High Pressure Hot-Pressing K Takatorn;M. Shimada;M. Koizumi