Chapter 26. Nondestructive Evaluation of Machining Damage in Silicon-Nitride Ceramic Valves

  1. Rajan Tandon,
  2. Andrew Wereszczak and
  3. Edgar Lara-Curzio
  1. J. G. Sun1,
  2. J. M. Zhang1 and
  3. J. S. Trethewey2

Published Online: 27 MAR 2008

DOI: 10.1002/9780470291313.ch26

Mechanical Properties and Performance of Engineering Ceramics II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 2

Mechanical Properties and Performance of Engineering Ceramics II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 2

How to Cite

Sun, J. G., Zhang, J. M. and Trethewey, J. S. (2006) Nondestructive Evaluation of Machining Damage in Silicon-Nitride Ceramic Valves, in Mechanical Properties and Performance of Engineering Ceramics II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 2 (eds R. Tandon, A. Wereszczak and E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291313.ch26

Author Information

  1. 1

    Argonne National Laboratory Argonne, IL 60439

  2. 2

    Caterpillar Inc. Peoria, IL 61656

Publication History

  1. Published Online: 27 MAR 2008
  2. Published Print: 1 JAN 2006

ISBN Information

Print ISBN: 9780470080528

Online ISBN: 9780470291313

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Keywords:

  • nondestructive evaluation (NDE);
  • acquisition;
  • backscatter;
  • circumference;
  • circumferential

Summary

In this study, we investigated machining–induced damage in silicon–nitride ceramic valves intended for use in diesel and natural–gas engines. A high–speed automated laser–scattering system was developed for the nondestructive evaluation (NDE) of several SN235P valves that were subjected to a coarse and a finish machining process. The valves were then tested in a bench rig. The NDE system scans the entire valve surface and generates a two–dimensional scattering image that is used to identify the location, size, and relative severity of subsurface damage from the machining process and from the rig tests. Machining damage in coarse–machined valves was significant. In particular, severe damage at the edge of the keeper groove caused premature failure of a valve under the rig test. After finish machining, it was found that most of the initial damage in the valves was removed. The data were analyzed and compared with surface photomicrographs.