Chapter 18. Fracture Toughness of Ceramics Using the Sevnb Method: Preliminary Results

  1. J. P. Singh
  1. Jakob Kübler

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294444.ch18

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4

How to Cite

Kübler, J. (1997) Fracture Toughness of Ceramics Using the Sevnb Method: Preliminary Results, in Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4 (ed J. P. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294444.ch18

Author Information

  1. Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1997

ISBN Information

Print ISBN: 9780470375532

Online ISBN: 9780470294444

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Keywords:

  • silicon nitride;
  • sintered;
  • specimens;
  • v-notches;
  • stress intensity

Summary

Many methods are currently used to measure the fracture toughness of ceramic materials. Procedures based on a widely accepted theory are often difficult to realise, unreliable, or expensive. The Single-Edge-Notched Beam (SENB) method was developed as a simple and inexpensive alternative, but the results can be influenced by the tip radius of the sawed notch. Recently a technique was introduced to taper a saw cut to a sharp tip radius using a razor blade sprinkled with diamond paste. This leads to V-notches, hence the name Single-Edge-V-Notched Beam (SEVNB). An aim of this study was to evaluate whether the method is user-friendly, reliable, and most importantly, how well its results compare with other methods. Fracture toughness values measured on alumina, silicon carbide, silicon nitride and a composite, all used in previous international fracture toughness round robin tests, compared well with values measured with the Single-Edge-Precracked Beam (SEPB), Surface Crack in Flexure (SCF) and Chevron Notch (CN) tests. Values measured on fine grained zirconia were in the range of values from the SCF method, but significantly lower than values from the CN method. The results exhibited only a small statistical spread. Therefore, the user-friendly SEVNB method is a potential standard test method and should be studied further.