47. Laser Scattering characterization of Subsurface Defect/Damage in Silicon-Nitride Ceramic Valves

  1. Edgar Lara-Curzio and
  2. Michael J. Readey
  1. J. G. Sun1,
  2. J. M. Zhang1 and
  3. M. J. Andrews2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291191.ch47

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

How to Cite

Sun, J. G., Zhang, J. M. and Andrews, M. J. (2004) Laser Scattering characterization of Subsurface Defect/Damage in Silicon-Nitride Ceramic Valves, in 28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4 (eds E. Lara-Curzio and M. J. Readey), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291191.ch47

Author Information

  1. 1

    Argonne National Laboratory Argonne, IL 60439

  2. 2

    Caterpillar Inc. Mossville, IL 61552

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2004

ISBN Information

Print ISBN: 9780470051528

Online ISBN: 9780470291191

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Keywords:

  • niobium-doped lead zirconate-titanate composition;
  • lower porosity ceramic;
  • solid matrix;
  • spherical shell;
  • volume strain

Summary

An automated laser-scattering system for nondestructive evaluation (NDE) was developed to scan silicon-nitride engine valves for distributed subsurface defects/damage. The technique is based on a cross-polarization detection method that measures only the optical scattering from the subsurface. The system utilizes two-rotation and two-translation stages to align and focus the laser beam on the valve surface during the entire scan, and the resulting two-dimensional scattering image is used to identify the location, size, and relative severity of subsurface defects. Laser-scattering images were obtained for two silicon-nitride valves made from NT551 (Norton-Saint Gobain) that were subjected to ambient-temperature cyclic-impact loads for 100 hours. These data were analyzed and compared with surface photomicroscopy results.