Chapter 6. Aluminum Oxynitride Spinel (ALON)–A New Optical and Multimode Window Material

  1. William Smothers
  1. T. M. Hartnett1,
  2. E. A. Maguire1,
  3. R. L. Gentilman1,
  4. N. D. Corbin2 and
  5. J. W. McCauley2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470318140.ch6

A Collection of Papers Presented at the 1981 New England Section Topical Meeting on Nonoxide Ceramics: Ceramic Engineering and Science Proceedings, Volume 3, No. 1/2

A Collection of Papers Presented at the 1981 New England Section Topical Meeting on Nonoxide Ceramics: Ceramic Engineering and Science Proceedings, Volume 3, No. 1/2

How to Cite

Hartnett, T. M., Maguire, E. A., Gentilman, R. L., Corbin, N. D. and McCauley, J. W. (2008) Aluminum Oxynitride Spinel (ALON)–A New Optical and Multimode Window Material, in A Collection of Papers Presented at the 1981 New England Section Topical Meeting on Nonoxide Ceramics: Ceramic Engineering and Science Proceedings, Volume 3, No. 1/2 (ed W. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470318140.ch6

Author Information

  1. 1

    Raytheon Research Division Waltham, MA 02254

  2. 2

    Army Materials & Mechanics Research Center Watertown, MA 02172

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1982

ISBN Information

Print ISBN: 9780470373934

Online ISBN: 9780470318140

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Keywords:

  • ultraviolet;
  • microstructure;
  • fabrication;
  • dielectric;
  • millimeter

Summary

Sintered aluminum oxynitride spinel (ALON) has been made window-glass transparent to ultraviolet, visible, and infrared wavelengths. Minimum in-line transmission from 0.3 to 5.0 μm is 74%. Sintering occurs in N2 from 1900o to 2000oC. Densities of at least 98% of theoretical are achieved in <1 h. A plot of log-grain size vs log time is linear with a slope of 0.42. Measurements of thermal/mechanical properties and dielectric properties made on 98% dense nontransparent ALON include: Knoop hardness of 1800 kg/mm2; elastic modulus of 3.2 × 105 MPa;flexural strength of 256 MPa; and a thermal expansion coefficient (25o to 1000oC) of 7.0×10−6/oC. The room-temperature dielectric constant and loss tangent are 10 MHz of 8.56 and 0.0004, respectively.