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Influence of additive composition on thermal and mechanical properties of ß–Si3N4 ceramics

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Abstract

Dense ß–Si3N4 ceramics were fabricated from α–Si3N4 raw powder by gas-pressure sintering at 1900 °C for 12 h under a nitrogen pressure of 1 MPa, using four different kinds of additive compositions: Yb2O3–MgO, Yb2O3–MgSiN2, Y2O3–MgO, and Y2O3–MgSiN2. The effects of additive composition on the microstructure and thermal and mechanical properties of ß–Si3N4 ceramics were investigated. It was found that the replacement of Yb2O3 by Y2O3 has no significant effect on the thermal conductivity and fracture toughness, but the replacement of MgO by MgSiN2 leads to an increase in thermal conductivity from 97 to 113 Wm-1K-1and fracture toughness from 8 to 10 MPa m1/2, respectively. The enhanced thermal conductivity of the MgSiN2-doped materials is attributed to the purification of ß–Si3N4 grain and increase of Si3N4–Si3N4 contiguity, resulting from the enhanced growth of large elongated grains. The improved fracture toughness of the MgSiN2-doped materials is attributed to the increase of grain size and fraction of large elongated grains. However, the same thermal conductivity between the Yb2O3- and Y2O3-doped materials is related to not only their similar microstructures, but also the similar abilities of removing oxygen impurity in Si3N4 lattice between Yb2O3 and Y2O3. The same fracture toughness between the Yb2O3- and Y2O3-doped materials is consistent with their similar microstructures. This work implies that MgSiN2 is an effective sintering aid for developing not only high thermal conductivity (>110 Wm-1K-1) but also high fracture toughness (>10 MPa m1/2) of Si3N4 ceramics.

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References

  1. K. Hirao, K. Watari, M.E. Brito, M. Toriyama, and S. Kanzaki: High thermal conductivity in silicon nitride with anisotropic microstructure. J. Am. Ceram. Soc. 79, 2485 (1996).

    Article  CAS  Google Scholar 

  2. Y. Okamoto, N. Hirosaki, M. Ando, F. Munakata, and Y. Akimune: Effect of sintering additive composition on the thermal conductivity of silicon nitride. J. Mater. Res. 13, 3473 (1998).

    Article  CAS  Google Scholar 

  3. K. Watari, K. Hirao, M.E. Brito, M. Toriyama, and S. Kanzaki: Hot isostatic pressing to increase thermal conductivity of Si3N4 ceramics. J. Mater. Res. 14, 1538 (1999).

    Article  CAS  Google Scholar 

  4. H. Hayashi, K. Hirao, M. Toriyama, S. Kanzaki, and K. Itatani: MgSiN2 addition as a means of increasing the thermal conductivity of _–silicon nitride. J. Am. Ceram. Soc. 84, 3060 (2001).

    Article  CAS  Google Scholar 

  5. M. Kitayama, K. Hirao, K. Watari, M. Toriyama, and S. Kanzaki: Thermal conductivity of _–Si3N4: III, Effect of rare-earth (RE _ La, Nd, Gd, Y, Yb, and Sc) oxide additives. J. Am. Ceram. Soc. 84, 353 (2001).

    Article  CAS  Google Scholar 

  6. H. Yokota, H. Abe, and M. Ibukiyama: Effect of lattice defects on the thermal conductivity of _- Si3N4. J. Eur. Ceram. Soc. 23, 1751 (2003).

    Article  CAS  Google Scholar 

  7. H. Yokota and M. Ibukiyama: Effect of the addition of _–Si3N4 nuclei on the thermal conductivity of _- Si3N4 ceramics. J. Eur. Ceram. Soc. 23, 1183 (2003).

    Article  CAS  Google Scholar 

  8. A.V. Virkar, T.B. Jackson, and R.A. Cutler: Thermodynamic and kinetic effects of oxygen removal on the thermal conductivity of aluminum nitride. J. Am. Ceram. Soc. 72, 2031 (1989).

    Article  CAS  Google Scholar 

  9. T.B. Jackson, A.V. Virkar, K.L. More, R.B. Dinwiddie, Jr., and R.A. Cutler: High-thermal-conductivity aluminum nitride ceramics: The effect of thermodynamic, kinetic, and microstructural factors. J. Am. Ceram. Soc. 80, 1421 (1997).

    Article  CAS  Google Scholar 

  10. M. Kitayama, K. Hirao, A. Tsuge, K. Watari, M. Toriyama, and S. Kanzaki: Thermal conductivity of _–Si3N4: II. Effect of lattice oxygen. J. Am. Ceram. Soc. 83, 1985 (2000).

    Article  CAS  Google Scholar 

  11. H. Hayashi, K. Hirao, M. Kitayama, S. Kanzaki, and K. Itatani: Effect of oxygen content on thermal conductivity of sintered silicon nitride. J. Ceram. Soc. Jpn. 109, 1046 (2001).

    Article  CAS  Google Scholar 

  12. K. Hirao, K. Watari, H. Hayashi, and M. Kitayama: High thermal conductivity silicon nitride. MRS Bull. 26, 451 (2001).

    Article  CAS  Google Scholar 

  13. M. Kitayama, K. Hirao, M. Toriyama, and S. Kanzaki: Thermal conductivity of _–Si3N4: I, Effects of various microstructural factors. J. Am. Ceram. Soc. 82, 3105 (1999).

    Article  CAS  Google Scholar 

  14. H. Yokota, S. Yamada, and M. Ibukiyama: Effect of large _–Si3N4 particles on the thermal conductivity of _–Si3N4 ceramics. J. Eur. Ceram. Soc. 23, 1175 (2003).

    Article  CAS  Google Scholar 

  15. A.D. Pablos, M.I. Osendi, and P. Miranzo: Effect of microstructure on the thermal conductivity of hot-pressed silicon nitride materials. J. Am. Ceram. Soc. 85, 200 (2002).

    Article  Google Scholar 

  16. N. Hirosaki, Y. Okamoto, M. Ando, F. Munakata, and Y. Akimune: Thermal conductivity of gas-pressure–Sintered silicon nitride. J. Am. Ceram. Soc. 79, 2878 (1996).

    Article  CAS  Google Scholar 

  17. J. Ye, N. Kojima, K. Furuya, F. Munakata, and A. Okada: Microthermal analysis of thermal conductance distribution in advanced silicon nitrides. J. Therm. Anal. Calorim. 69, 1031 (2002).

    Article  CAS  Google Scholar 

  18. Z. Lencˇe´sˇ, K. Hirao, Y. Yamauchi, and S. Kanzaki: Reaction synthesis of magnesium silicon nitride powder. J. Am. Ceram. Soc. 86, 1088 (2003).

    Article  Google Scholar 

  19. T. Nose and T. Fujii: Evaluation of fracture toughness for ceramic materials by a single-edge-precracked-beam method. J. Am. Ceram. Soc. 71, 328 (1988).

    Article  CAS  Google Scholar 

  20. C. Greskovich and S. Prochazka: Stability of Si3N4 and liquid phase(s) during sintering. J. Am. Ceram. Soc. 64, C-96 (1981).

    Article  Google Scholar 

  21. F.F. Lang: Volatilization associated with the sintering of polyphase Si3N4 materials. J. Am. Ceram. Soc. 65, C-120 (1982).

    Article  Google Scholar 

  22. S. Baik and R. Raj: Effect of silicon activity on liquid-phase sintering of nitrogen ceramics. J. Am. Ceram. Soc. 68, C-124 (1985).

    Article  Google Scholar 

  23. W.J. Kim, D.Y. Kim, and C.H. Kim: Morphological effect of second phase on the thermal conductivity of AlN ceramics. J. Am. Ceram. Soc. 79, 1066 (1996).

    Article  CAS  Google Scholar 

  24. F. Boey, A.I.Y. Tok, Y.C. Lam, and S.Y. Chew: On the effects of secondary phase on thermal conductivity of AlN ceramic substrates using a microstructural modelling approach. Mater. Sci. Eng. A 335, 281 (2002).

    Article  Google Scholar 

  25. W. Dressler, H.J. Kleebe, M.J. Hoffmann, M. Rühle, and G. Petzow: Model experiments concerning abnormal grain growth in silicon nitride. J. Eur. Ceram. Soc. 16, 3 (1996).

    Article  CAS  Google Scholar 

  26. H. Björklund, L.K.L. Falk, K. Rundgren, and J. Wasén:–Si3N4 grain growth, Part I: Effect of metal oxide sintering additives. J. Eur. Ceram. Soc. 17, 1285 (1997).

    Article  Google Scholar 

  27. H.J. Kleebe, G. Pezzotti, and G. Ziegler: Microstructure and fracture toughness of Si3N4 ceramics: Combined roles of grain morphology and secondary phase chemistry. J. Am. Ceram. Soc. 82, 1857 (1999).

    Article  CAS  Google Scholar 

  28. R. Ramesh, E. Nestor, M.J. Pomeroy, and S. Hampshire: Formation of Ln-Si-Al-O-N glasses and their properties. J. Eur. Ceram. Soc. 17, 1933 (1997).

    Article  CAS  Google Scholar 

  29. K.T. Faber and A.G. Evans: Crack deflection processes: Theory and experiment. Acta Metall. 31, 565 (1983).

    Article  Google Scholar 

  30. P.F. Becher: Microstructural design of toughened ceramics. J. Am. Ceram. Soc. 74, 255 (1991).

    Article  CAS  Google Scholar 

  31. H.J. Park, H.E. Kim, and K. Niihara: Microstructural evolution and mechanical properties of Si3N4 with YB2O3 as a sintering additive. J. Am. Ceram. Soc. 80, 750 (1997).

    Article  CAS  Google Scholar 

  32. M.J. Hoffman: In Tailoring of Mechanical Properties of Si3N4Ceramics, edited by M.J. Hoffmann and G. Petzow (NATO ASI Series E: Applied Sciences, Vol. 276, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1993), pp. 233–244.

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Zhu, X., Hayashi, H., Zhou, Y. et al. Influence of additive composition on thermal and mechanical properties of ß–Si3N4 ceramics. Journal of Materials Research 19, 3270–3278 (2004). https://doi.org/10.1557/JMR.2004.0416

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  • DOI: https://doi.org/10.1557/JMR.2004.0416

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