AlN ceramics processed by aqueous slip casting

Abstract

Fully dense aluminium nitride (AlN) ceramics consolidated by aqueous slip casting were obtained after sintering at 1750 °C for 2 h. The obtained samples were characterized by Vickers hardness (1000 Hv), flexural strength (200 MPa) and thermal conductivity (115 W/mK). YF3 and CaF2 were used as sintering additives in total amounts ranging from 5 to 7 wt% in YF3/CaF2 weight ratios of 1.25, 1.5, and 2. The compatibility between the thermochemically treated AlN powder and the sintering additives in the aqueous suspensions was investigated by rheological and zeta potential measurements. Highly concentrated (50 vol%) and well-dispersed suspensions could be prepared and used to consolidate homogeneous green bodies by slip casting. The phosphate species used to protect the surface AlN particles against hydrolysis could no longer be detected at temperatures higher than 1400 °C. X-ray diffraction results revealed that all the new crystalline phases formed upon sintering belong to the system Al–Y–O–Ca, but their specific compositions as well as the thermal properties of the sintered materials were shown to depend on the total amount and ratio of sintering aids.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    L.M. Sheppard: Aluminium nitride: A versatile but challenging material. Am. Ceram. Soc. Bull. 69, 1801 (1990).

    Google Scholar 

  2. 2.

    A.K. Knudsen: Aluminum nitride. Am. Ceram. Soc. Bull. 74, 97 (1995).

    CAS  Google Scholar 

  3. 3.

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

    CAS  Article  Google Scholar 

  4. 4.

    A. Collange, P. Grosseau, B. Guilhot, J.P. Disson, P. Joubert: Thermal conductivity of compacted AlN samples. J. Eur. Ceram. Soc. 17, 1897 (1997).

    CAS  Article  Google Scholar 

  5. 5.

    P. Greil, M. Kulig, D. Hotza: Aluminium nitride ceramics with high thermal conductivity from gas-phase synthesized powders. J. Eur. Ceram. Soc. 13, 229 (1994).

    CAS  Article  Google Scholar 

  6. 6.

    Y. Ying-Da, A.M. Hundere, R. Hoier, R.E. Dunin-Borkowski, M.A. Einarsrud: Microstructural characterization and microstructural effects on the thermal conductivity of AlN (Y2O3) ceramics. J. Eur. Ceram. Soc. 22, 247 (2002).

    Article  Google Scholar 

  7. 7.

    H. Buhr, G. Muller: Microstructure and thermal conductivity of AlN (Y2O3) ceramics sintered in different atmospheres. J. Eur. Ceram. Soc. 12, 271 (1993).

    CAS  Article  Google Scholar 

  8. 8.

    U. Neumann, T. Reetz: The influence of the anions of calcium-containing sintering aids for aluminium nitride. J. Eur. Ceram. Soc. 12, 117 (1993).

    CAS  Article  Google Scholar 

  9. 9.

    K. Watari, J.H. Hwang, M. Toriyama, S. Kanzaki: Effective sintering aids for low-temperature sintering of AlN ceramics. J. Mater. Res. 14, 1409 (1999).

    CAS  Article  Google Scholar 

  10. 10.

    Y. Liu, H. Zhou, L. Qiao, Y. Wu: Low-temperature sintering of aluminium nitride with YF3–CaF2 binary additive. J. Mater. Sci. Lett. 18, 703 (1999).

    CAS  Article  Google Scholar 

  11. 11.

    A.M. Hundere, M.A. Einarsrud: Effects of reduction of the Al–Y–O containing secondary phases during sintering of AlN with YF3 additions. J. Eur. Ceram. Soc. 16, 899 (1996).

    CAS  Article  Google Scholar 

  12. 12.

    L. Qiao, H. Zhou, R. Fu: Thermal conductivity of AlN ceramics sintered with CaF2 and YF3. Ceram. Int. 29, 893 (2003).

    CAS  Article  Google Scholar 

  13. 13.

    F.F. Lange: Powder processing science and technology for increased reliability. J. Am. Ceram. Soc. 72, 3 (1989).

    CAS  Article  Google Scholar 

  14. 14.

    W.E. Lee, W.M. Rainforth: Ceramic Microstructure-Property Control by Processing (Chapman and Hall, London, UK, 1994).

    Google Scholar 

  15. 15.

    M.S. Wolfgang, S.B. Nelson, L. Bergstrom: Novel powder-processing methods for advanced ceramics. J. Am. Ceram. Soc. 83, 1557 (2000).

    Google Scholar 

  16. 16.

    F.F. Lange, K.T. Miller: A colloidal method to ensure phase homogeneity in β″–Al2O3/ZrO2 composite systems. J. Am. Ceram. Soc. 70, 896 (1987).

    CAS  Article  Google Scholar 

  17. 17.

    J. Lewis: Colloidal processing of ceramics. J. Am. Ceram. Soc. 83, 2341 (2000).

    CAS  Article  Google Scholar 

  18. 18.

    Z.S. Rak: Advanced shaping techniques in advanced ceramics. Ceram. Forum Int. 7766 (2000).

    Google Scholar 

  19. 19.

    G. Tarì, J.M.F Ferreira, O. Lyckefeldt: Influence of magnesia on colloidal processing of alumina. J. Eur. Ceram. Soc. 17, 1341 (1997).

    Article  Google Scholar 

  20. 20.

    G. Tarì, J.M.F Ferreira: Colloidal processing of calcium carbonate. Ceram. Int. 24, 527 (1998).

    Article  Google Scholar 

  21. 21.

    S.M. Olhero, S. Novak, K. Krnel, T. Kosmac, J.M.F Ferreira: Thermo-chemical surface treatment of AlN powder towards aqueous processing of AlN ceramics. J. Mater. Res. 19, 746 (2004).

    CAS  Article  Google Scholar 

  22. 22.

    M. Oliveira, S. Olhero, J. Rocha, J.M.F Ferreira: Controlling hydrolysis and dispersing AlN powders in aqueous media. J. Colloid Interface Sci. 261, 456 (2003).

    CAS  Article  Google Scholar 

  23. 23.

    S.M. Olhero, M.I.L.L Oliveira, J.M.F Ferreira: Successful strategies for aqueous colloidal shape-forming of nitride-based ceramics. Recent Devel. Coll. Inter. Res. 2, 65 (2004).

    CAS  Google Scholar 

  24. 24.

    K. Krnel, T. Kosmac: Reactivity of aluminium nitride powder in dilute inorganic acids. J. Am. Ceram. Soc. 83, 1375 (2000).

    CAS  Article  Google Scholar 

  25. 25.

    K. Krnel, T. Kosmac: Protection of AlN powder against hydrolysis using aluminium dihydrogen phosphate. J. Eur. Ceram. Soc. 21, 2075 (2001).

    CAS  Article  Google Scholar 

  26. 26.

    Y. Shimizu, J. Hatano, T. Hyodo, M. Egashira: Ion-exchange loading of yttrium acetate as a sintering aid on aluminium nitride powder via aqueous processing. J. Am. Ceram. Soc. 83, 2793 (2000).

    CAS  Article  Google Scholar 

  27. 27.

    X.J. Luo, X.R. Xu, B.L. Zhang, W.L. Li, H.R. Zhuang: Characteristic and dispersion of a treated AlN powder in aqueous solvent. Mater. Sci. Eng., A 368, 126 (2004).

    Article  Google Scholar 

  28. 28.

    J. Jarrige, K. Bouzouita, C. Doradoux, M. Billy: A new method for fabrication of dense aluminium nitride bodies at temperatures as low as 1600 °C. J. Eur. Ceram. Soc. 12, 279 (1993).

    CAS  Article  Google Scholar 

  29. 29.

    K. Watari, H.J. Hwang, M. Toriyama, S. Kanzaki: Effective sintering aids for low-temperature sintering of AlN ceramics. J. Mater. Res. 14, 1409 (1999).

    CAS  Article  Google Scholar 

  30. 30.

    T.B. Troczynski, P.S. Nicholson: Effect of additives on the pressureless sintering of aluminium nitride between 1500 and 1800 °C. J. Am. Ceram. Soc. 72, 1488 (1989).

    CAS  Article  Google Scholar 

  31. 31.

    E. Streicher, T. Chartier, P. Boch, M.F. Denanot, J. Rabier: Densification and thermal conductivity of low-sintering-temperature AlN materials. J. Eur. Ceram. Soc. 6, 23 (1990).

    CAS  Article  Google Scholar 

  32. 32.

    L. Qiao, H. Zhou, H. Xue, S. Wang: Effect of Y2O3 on low temperature sintering and thermal conductivity of AlN ceramics. J. Eur. Ceram. Soc. 23, 61 (2003).

    CAS  Article  Google Scholar 

  33. 33.

    P.G. Klemens: Thermal conductivity of inhomogeneous media. High Temp. High Press 23, 241–248, (1991).

    CAS  Google Scholar 

  34. 34.

    R.S. Roth, T. Negas, P.C. Lawrence: In Phase Diagrams for Ceramists, Vol. 5, edited by G. Smith (American Ceramic Society, Columbus, OH, 1983), p. 97.

    Google Scholar 

  35. 35.

    A.M. Hundere, M.A. Einarsurd: Microstructural development in AlN (YF3) ceramics. J. Eur. Ceram. Soc. 17, 873 (1997).

    CAS  Article  Google Scholar 

  36. 36.

    G. Gorzawski, M. Sternitzke, W.F. Muller, A. Berger, G. Muller: Oxygen enrichment at inversion domain boundaries in aluminium nitride—Influence on thermal conductivity. J. Eur. Ceram. Soc. 15, 95 (1995).

    CAS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to J. M. F. Ferreira.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Olhero, S.M., Miranzo, P. & Ferreira, J.M.F. AlN ceramics processed by aqueous slip casting. Journal of Materials Research 21, 2460–2469 (2006). https://doi.org/10.1557/jmr.2006.0301

Download citation