20. The Indentation Size Effect (ISE) for Knoop Hardness in Five Ceramic Materials

  1. Lisa Prokurat,
  2. Andrew Wereszczak and
  3. Edgar Lara-Curzio
  1. Trevor Wilantewicz1,
  2. W. Roger Cannon1 and
  3. George Quinn2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291368.ch20

Advances in Ceramic Armor II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 7

Advances in Ceramic Armor II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 7

How to Cite

Wilantewicz, T., Cannon, W. R. and Quinn, G. (2008) The Indentation Size Effect (ISE) for Knoop Hardness in Five Ceramic Materials, in Advances in Ceramic Armor II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 7 (eds L. Prokurat, A. Wereszczak and E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291368.ch20

Author Information

  1. 1

    Rutgers, The State University of New Jersey 607 Taylor Road Piscataway, NJ 08854

  2. 2

    National Institute of Standards and Technology Gaithersburg, MD 20899

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2006

ISBN Information

Print ISBN: 9780470080573

Online ISBN: 9780470291368

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Keywords:

  • ceramic materials;
  • knoop hardness;
  • severe cracking;
  • ballistic performance;
  • frictional effects

Summary

The variation of indentation hardness with contact load i.e., the indentation size effect (ISE), was investigated for five ceramic materials: (i) AlON, (ii) AD995 CAP3 Al2O3, (iii) pressureless-sintered SiC (Hexoloy SA), (iv) SiC-N, and (v) SiC-B. A Knoop diamond indenter was used to make indentations in the load range from 0.49 N (0.05 Kg) to 137.3 N (14 Kg). The Knoop hardness decreased approximately 26%, 38%, 36%, 32%, and 31% for the five materials, respectively, over the entire load range. The Knoop hardness of all five materials continued to decrease as the load was increased beyond 2 Kg. In addition, severe cracking around indentation sites generally correlated with a lower Knoop hardness compared to less-cracked indentation sites for the silicon carbide and AD995 CAP3 materials. Accurate hardness measurements are necessary in order to detect variability in hardness not attributable to operator or instrument differences, and which may yield insight into ballistic performance.