Chapter 45. A Modified Flaw-Size Toughness Technique

  1. Ersan Ustundag and
  2. Gary Fischman
  1. Jason A. Griggs1,
  2. Thomas J. Hill1 and
  3. John J. Mecholsky Jr.2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294567.ch45

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

How to Cite

Griggs, J. A., Hill, T. J. and Mecholsky, J. J. (1999) A Modified Flaw-Size Toughness Technique, in 23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3 (eds E. Ustundag and G. Fischman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294567.ch45

Author Information

  1. 1

    Dept. of Dental Biomaterials University of Florida 1600 SW Archer Road #D9–16 Gainesville, FL 32610

  2. 2

    Dept. of Materials Science and Engineering University of Florida 256A Rhines Hall Gainesville, FL 32611

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1999

ISBN Information

Print ISBN: 9780470375631

Online ISBN: 9780470294567

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Keywords:

  • indentation;
  • microstructures;
  • indentation;
  • replications;
  • intensity

Summary

A modified indentation technique for measuring fracture toughness without the use of residual stress parameters was previously described by Cook and Lawn.1 To determine the accuracy of this technique for testing glass-ceramics, barium aluminosilicate (BAS) glass-ceramics with a variety of microstructures were examined. Comparisons were made with the fracture toughness values calculated using a novel technique. The sizes of subcritical and critical flaws were compared. The modified flaw-size technique provided a closer estimate of fracture toughness than the modified indentation technique for all of the glass-ceramics examined. The semi-elliptical shape of indenter-induced flaws is responsible for the difference between test methods. These results explain a discrepancy between the theory and regression model of Cook and Lawn.