Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
권호 표지

A Study on the Strength-Probability-Time(SPT) Diagram for Sintered Silicon Nitride

소결질화규소에 있어서 Strength-Probability-Time Diagram 에 관한 연구

  • 하정수 (한국과학기술원 재료공학부) ;
  • 이준근 (한국과학기술원 재료공학부)
  • Published : 1985.04.01
Download PDF
⟨ Previous Next ⟩

Abstract

A composition containing a-$Si_3N_4$ with 5w/0 $Y_2O_3$ and 4w/0 $Al_2O_3$ was hot-pressed at 1, $650^{\circ}C$ and 350kg/$cm^2$ for 1.5hrs and specimens of the same composition were pressureless-sintered at 1, 75$0^{\circ}C$ for 1.5 and 5hrs. By X-ray diffraction it was found that hot-pressed specimens were consisted of $\alpha$-and $\beta$-$Si_3N_4$ and sintered specimens were consisted of $\beta$-$Si_3N_4$ and $Si_3N-4Y_2O_3$ which was crystallized out from the grainboundary phase. The 5-hr sintered specimens had higher degree of crystallization than the 1.5 hr sintered specimens. Among these three different specimens the 5-hr sintered specimens showed the highest strength by hot MOR test at 1, 00$0^{\circ}C$. The SPT diagram for the 5-hr sintered $Si_3N_4$ was constructed by measurements of the stress rate dependence of fracture strength.

Keywords

References

  1. J. Mat. Sci v.10 no.1169-1174 Presssureless Sintering of Si₃N₄ G.R. Terwilliger;F.F. Lange
  2. Proc. Workshop on Ceramics for Advanced Heat Engines, Energy Res. and Dev. Adm. CONRT v.191-196 Sintering of silicon Niitride D.J. Rowcliffe;P.J. Jorgensen
  3. Yogyo-Kyokai-Shi v.85 no.8 Sintering of Si₃N₄with Al₂O₃and Y₂O₃ M. Mitomo
  4. Proc. Int. Sym. Factors Densification and Sintering Oxide Nonoxide Ceramics v.426-442 A Study of Sintered Si₃N₄Compositions with Y₂O₃and Al₂O₃Densification Additives J.T. Smith;C.L. Quackenbusb
  5. Ceramics for Vehicular Engines: STATE-OF-THE-ART, Materials Science Monographs 6-Energy and Ceramics R.N. Katz;P. Vincenzini(ed.)
  6. J. Mal. Sci v.8 no.1699-1705 Strength-Probability-Time(SPT) Relationships in Ceramics R.W. Davidge;J.R. McLaren;G. Tappin
  7. J. Am. Ceram. Soc v.57 no.2 High-Temperature Strength Beha vion of Hot-Pressed Si₃N₄: Evidence for Subcritical Crack Growth F.F. Lange
  8. J. Am. Ceram. Soc v.57 no.1 Hot-Pressing Behavior of Si₃N₄ G.R. Terwilliger;F.F. Lange
  9. Am. Ceram. Soc. Bull v.56 no.9 Determination of Phase Content of Si₃N₄by X-ray Diffraction Analysis C.P. Gazzara;D.R. Messier
  10. J. Am. Ceram. Soc v.66 no.1 Microstructure and Grain-Boundary Composition of Hot-Pressed Silicon Nitride with Yttria and Alumina C.C. Ahn;G. Thomas
  11. Am. Ceram. Soc. Bull v.57 no.4 High Strength Hot Pressed Si₃N₄with Concurrent Y₂O₃and Al₂O₃Additives A. Tsuge;K. Nishida
  12. J. Am. Ceram. Soc v.56 no.518-522 Relation Between Strength, Fracture Energy and Microstructure of Hot-Pressed Si₃N₄ F.F. Lange
  13. Appl. Sci. Pub. Ltd v.122-134 Fracture of Engineering Brittle Materials A.S. Jayatilaka
  14. Am. Ceram. Soc. Bull v.59 no.9 Phase Effects in Si₃N₄Containing Y₂O₃or CeO₂ I. Strength J.T. Smith;C.L. Quackenbush