Advertisement

Journal of Materials Science

, Volume 31, Issue 13, pp 3453–3458 | Cite as

Sol-gel processing and sintering of yttrium aluminum garnet (YAG) powders

  • R. Manalert
  • M. N. Rahaman
Papers

Abstract

Gels of yttrium aluminum garnet (YAG) with the stoichiometric composition 3Y2O3·5AI2O3, were prepared by a sol-gel technique and dried by supercritical extraction with CO2. Powders were produced by lightly grinding the dried gels. Crystallization of the powder occurred at ≈900°C and within the limits of detection, the X-ray diffraction pattern of the crystallized material was identical to that of the stoichiometric composition. Powder compacts with a green density of ≈0.50 of the theoretical were sintered to nearly full density in O2 during constant heating rate sintering at 5 °C min−1 to 1600 °C. This is better than the density obtained with powders from a similar gel dried conventionally (by evaporation of the liquid) and considerably better than that obtained with powders prepared by solid state reaction. The room temperature flexural strength and fracture toughness of the material fabricated from the supercritically dried gels were 190 MPa and 2.2 MPa.m1/2, respectively. These strength and fracture toughness values are higher than those reported in other studies for YAG produced by the sintering route.

Keywords

Crystallization Fracture Toughness Yttrium Solid State Reaction Flexural Strength 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    O. Yamaguchi, K. Matui and K. Shimizu, Ceramics Internat. 11 (1985) 107.CrossRefGoogle Scholar
  2. 2.
    J. Machan, R. Kurtz, M. Bess and M. Birnbaum, Optical Society of America (Technical Digest Series) 20 (1987) 134.Google Scholar
  3. 3.
    D. R. Messier and G. E. Gazza, Amer. Ceram. Soc. Bull. 51 (1972) 692.Google Scholar
  4. 4.
    G. Dewith and H. S. A. van Dijk, Mater. Res. Bull. 19 (1984) 1669.CrossRefGoogle Scholar
  5. 5.
    V. B. Glushkova, O. N. Egorova, V. A. Krzhizhanorskaya, and K. Yu. Merezhinskii, Inorg. Mater. 19 (1983) 1015.Google Scholar
  6. 6.
    L. P. Morozova, E. S. Lukin, T. V. Efimovskaya, A. V. Smolya and I. F. Panteleeva, Glass Ceramics 35 (1978) 158.CrossRefGoogle Scholar
  7. 7.
    K. Keller, T.-I. Mah and T. Parthasarathy, Ceram. Eng. Sci. Proc. 11 (1990) 1122.CrossRefGoogle Scholar
  8. 8.
    G. Gowda, J. Mater. Sci. Lett. 5 (1986) 1029.CrossRefGoogle Scholar
  9. 9.
    C. J. Brinker and G. W. Scherer, “Sol-Gel Science”, (Academic Press, New York, 1990).Google Scholar
  10. 10.
    M. N. Rahaman and D. Y. Jeng, Ceramic Trans. 7 (1990) 753.Google Scholar

Copyright information

© Chapman & Hall 1996

Authors and Affiliations

  • R. Manalert
    • 1
  • M. N. Rahaman
    • 1
  1. 1.Department of Ceramic EngineeringUniversity of Missouri-RollaRollaUSA

Personalised recommendations