11. Geometry of Edge Chips Formed at Different Angles

  1. Edgar Lara-Curzio
  1. Janet Quinn and
  2. Ram Mohan

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291221.ch11

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

Quinn, J. and Mohan, R. (2005) Geometry of Edge Chips Formed at Different Angles, 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.ch11

Author Information

  1. American Dental Association Foundation National Institute of Standards and Technology, 100 Bureau Drive, STOP 8546 Gaithersburg, MD 20899-8546

Publication History

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

ISBN Information

Print ISBN: 9781574982329

Online ISBN: 9780470291221

SEARCH

Keywords:

  • edge chip test;
  • annealed soda lime glass;
  • cobalt;
  • porcelains;
  • glass tests

Summary

In the edge-chip test, an increasing force is applied near the edge of a specimen until a chip is formed. At greater distances from the specimen edge, higher forces are required for chip formation. A plot can be constructed by graphing the force necessary to form a chip against the distance from the specimen edge where the force is applied. The slope of the line resulting from such a plot constitutes the edge toughness. Studies have shown that chip geometries are self-similar, such that the chip width, depth and height ratios are independent of material or total chip size. Such previous studies, however, refer to edge chips made with a force perpendicular to the specimen surface. The current work addresses the issues of applied force direction and subsequent changes in edge toughness and chip geometry when chips are formed from forces that are not perpendicular. Greater force is required to produce a chip when the force is angled away from the edge, for example, and some aspects of the resulting chip geometry resemble a flattened cone. Quantitative analyses of such geometric changes can enable back calculation of force and direction in performing edge chip failure analyses, and would aid in designing components for edge integrity when the forces are not perpendicular.