33. Mechanical Responses of Silicon Nitrides Under Dynamic Endentation

  1. Edgar Lara-Curzio
  1. Hong Wang and
  2. Andrew A. Wereszczak

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291221.ch33

Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2

Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2

How to Cite

Wang, H. and Wereszczak, A. A. (2005) Mechanical Responses of Silicon Nitrides Under Dynamic Endentation, in Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2 (ed E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291221.ch33

Author Information

  1. Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, TN 37831-6068

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982329

Online ISBN: 9780470291221

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Keywords:

  • indentation size effect;
  • silicon nitrides;
  • split-hopkinson pressure bar system;
  • scanning electron microscope;
  • fracture toughness

Summary

Mechanical responses of five silicon nitrides have been experimentally studied by using dynamic and standard hardness tests. The indentation loads ranged from several newtons to several hundred newtons. In the dynamic test, a load pulse with ∼ 100 m̈s rise time was achieved. Indentation size effect (ISE) and loading rate effects on the Vickers hardness were observed for the silicon nitrides. The ISE was further characterized by using the Meyer law and the energy-balance or proportional specimen resistance (PSR) model. The conventional brittleness approach is not satisfactory in characterizing transition between plasticity and fracture, and a new brittleness concept is proposed based on the PSR model that appears to capture the dynamic indentation responses of the materials.