Materials Transactions Online

Materials Transactions, Vol.46 No.05 (2005) pp.996-1003
© 2005 The Japan Institute of Metals

Effect of Chemical Composition on the Optical Properties and Fracture Toughness of Transparent Magnesium Aluminate Spinel Ceramics

Arcan F. Dericioglu1,, Aldo R. Boccaccini2, Ivo Dlouhy3 and Yutaka Kagawa1,

1Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
2Department of Materials, Imperial College London, London SW7 2BP, UK
3Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno 61662, Czech Republic

Polycrystalline transparent magnesium aluminate ``spinel'' ceramics were fabricated by hot-pressing and hot isostatic pressing (HIPing) using commercially available MgO and Al2O3 powders. Al2O3 content of spinel was systematically changed that can be expressed as MgO⋅nAl2O3 with n=1.0, 1.5 and 2.0. UV/visible and near-IR wavelength region light reflection and transmission behaviors of the spinel ceramics were quantitatively correlated to their microstructure to account for the optical quality of the fabricated materials. The stoichiometric spinel ceramic with n=1.0 revealed a relatively poor optical transparency due to pronounced light scattering at the microcracked grain boundaries with a specular light transmission of ∼20--40% in the visible wavelength range. On the other hand, Al2O3 rich compositions revealed a specular transmission of ∼40--60% in the same wavelength range with a high degree of transparency. Additionally, effect of chemical composition on the fracture toughness of spinel ceramics was investigated applying indentation and chevron notched specimen fracture toughness measurement techniques. The spinel ceramic with n=2.0 revealed the highest fracture toughness with a mean value of ∼2.02 MPa·m1/2. Based on their optical and mechanical properties, potential of Al2O3$ rich non-stoichiometric polycrystalline spinel ceramics for engineering applications requiring high optical transparency and improved fracture toughness was addressed.

(Received 2004/12/27; Accepted 2005/3/11)

Keywords: MgAl2O4 spinel, optical properties, fracture toughness, microcracking

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REFERENCES

  1. R. J. Bratton: J. Am. Ceram. Soc. 57 (1974) 283--286.
  2. M. C. L. Patterson, J. E. Caiazza and D. W. Roy: Proc. SPIE 4102 (2000) 59--68.
  3. G. Gilde, P. Patel and M. Patterson: Proc. SPIE 3705 (1999) 94--104.
  4. D. W. Roy and G. G. Martin, Jr.: Proc. SPIE 1760 (1992) 2--13.
  5. J. J. Swab, J. C. LaSalvia, G. A. Gilde, P. J. Patel and M. J. Motyka: Ceram. Eng. Sci. Proc. 20 (1999) 79--84.
  6. D. W. Roy and J. L. Hastert: Ceram. Eng. Sci. Proc. 4 (1983) 502--509.
  7. D. S. Tsai, C. T. Wang, S. J. Yang and S. E. Hsu: Mater. Manuf. Processes 9 (1994) 709--719.
  8. K. E. Green, J. L. Hastert and D. W. Roy: Proc. SPIE 1112 (1989) 2--8.
  9. M. Shimada, T. Endo, T. Saito and T. Sato: Mater. Lett. 28 (1996) 413--415.
  10. D. W. Roy: Proc. SPIE 297 (1981) 13--18.
  11. K. Hamano and S. Kanzaki: Yogyo-Kyokai-Shi 85 (1977) 225--230.
  12. S. Kanzaki, K. Saito, Z. Nakagawa and K. Hamano: Yogyo-Kyokai-Shi 86 (1978) 485--491.
  13. A. F. Dericioglu and Y. Kagawa: J. Eur. Ceram. Soc. 23 (2003) 951--959.
  14. E. M. Levin and H. F. McMurdie: Phase Diagrams for Ceramists 1975 Supplement, (The American Ceramic Society Inc., Ohio, 1975) pp.~114, 135.
  15. G. R. Anstis, P. Chantikul, B. R. Lawn and D. B. Marshall: J. Am. Ceram. Soc. 64 (1981) 533--538.
  16. A. R. Boccaccini, R. D. Rawlings and I. Dlouhy: Mater. Sci. Eng. A 347 (2003) 102--108.
  17. J. I. Bluhm: Eng. Fract. Mech. 7 (1975) 593--604.
  18. National Bureau Standards (U.S.) Monogr. 25 (1971) 9--25.
  19. M. Erneta and H. A. Stockler: J. Am. Ceram. Soc. 56 (1973) 394--395.
  20. J. G. J. Peelen and R. Metselaar: J. Appl. Phys. 45 (1974) 216--220.
  21. M. Baas (Editor in Chief): Handbook of Optics v. II, (McGraw-Hill Inc., New York, 1995) p.~33.19.
  22. W. L. Wolfe and G. J. Zissis: The Infrared Handbook, (ONR, Department of Navy, Washington, 1978) p.~5--70.
  23. W. G. Driscoll and W. Vanghan: Handbook of Optics, (McGraw-Hill Inc., New York, 1978) p.~7.52.
  24. E. Hecht: Optics, (Addison-Wesley Publishing Company Inc., New York, 2002) p.~67.
  25. J. Schroeder and J. H. Rosolowski: Proc. SPIE 297 (1981) 156--168.
  26. K. Ahlborn, Y. Kagawa and A. Okura: Fracture Mech. Ceram. 10 (1992) 47--58.
  27. K. J. Kurzydlowski and B. Ralph: The Quantitative Description of the Microstructure of Materials, (CRC Press Inc., Boca Raton, 1995) p.~20.
  28. K. J. Kurzydlowski and B. Ralph: The Quantitative Description of the Microstructure of Materials, (CRC Press Inc., Boca Raton, 1995) p.~275.
  29. J. C. Hay and K. W. White: Fracture Mechanics of Ceramics, ed. by R. C. Bradt et al., (Plenum Press, New York, 1992) p.~265.

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