Chapter 96. Fracture Strength of Large Area, Edge-Bonded Sapphire

  1. Hua-Tay Lin and
  2. Mrityunjay Singh
  1. D. Fiore1,
  2. R. Gentilman1,
  3. P. Mcguire1 and
  4. R. N. Katz2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294741.ch96

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

How to Cite

Fiore, D., Gentilman, R., Mcguire, P. and Katz, R. N. (2008) Fracture Strength of Large Area, Edge-Bonded Sapphire, in 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3 (eds H.-T. Lin and M. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294741.ch96

Author Information

  1. 1

    Materials Systems Inc. Littleton, MA 01460

  2. 2

    Worcester Polytechnic Institute Worcester, MA 01609

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375785

Online ISBN: 9780470294741

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Keywords:

  • diffusion;
  • edge-bonding;
  • polycrystalline;
  • sapphire;
  • crystallographic

Summary

New high performance optical systems which require highly durable, broadband window materials demand larger window sizes than those currently available. To meet this need, a low cost edge-bonding process was developed for producing large area sapphire windows from smaller, melt-grown blanks. The method uses an alumina fillet to promote diffusion and single crystal conversion at the bond line and produce high strength bonds. The current research investigates the effect of the fillet composition on the mechanical strength of the bonded sapphire. Bonding trials were conducted using alumina fillet materials with various chemical additives. The fracture strengths of bonded sapphire samples were characterized by four-point flexure testing and Weibull analysis. Fracture strengths as high as 255 MPa (37 kpsi) were measured for the bonded sapphire.