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Title: Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings

Abstract

Apparatus detects defects and microstructural changes in hard translucent materials such as ceramic bulk compositions and ceramic coatings such as after use under load conditions. The beam from a tunable laser is directed onto the sample under study and light reflected by the sample is directed to two detectors, with light scattered with a small scatter angle directed to a first detector and light scattered with a larger scatter angle directed to a second detector for monitoring the scattering surface. The sum and ratio of the two detector outputs respectively provide a gray-scale, or "sum" image, and an indication of the lateral spread of the subsurface scatter, or "ratio" image. This two detector system allows for very high speed crack detection for on-line, real-time inspection of damage in ceramic components. Statistical image processing using a digital image processing approach allows for the quantative discrimination of the presence and distribution of small flaws in a sample while improving detection reliability. The tunable laser allows for the penetration of the sample to detect defects from the sample's surface to the laser's maximum depth of penetration. A layered optical fiber directs the incoming laser beam to the sample and transmits each scattered signalmore » to a respective one of the two detectors.« less

Inventors:
 [1];  [2];  [3]
  1. (Naperville, IL)
  2. (Hinsdale, IL)
  3. (Westmont, IL)
Issue Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL
OSTI Identifier:
873971
Patent Number(s):
6285449
Assignee:
University of Chicago (Chicago, IL) ANL
DOE Contract Number:  
W-31109-ENG-38
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
optical; method; apparatus; detection; defects; microstructural; changes; ceramics; ceramic; coatings; detects; hard; translucent; materials; bulk; compositions; load; conditions; beam; tunable; laser; directed; sample; study; light; reflected; detectors; scattered; scatter; angle; detector; larger; monitoring; scattering; surface; ratio; outputs; respectively; provide; gray-scale; image; indication; lateral; spread; subsurface; allows; speed; crack; on-line; real-time; inspection; damage; components; statistical; processing; digital; approach; quantative; discrimination; presence; distribution; flaws; improving; reliability; penetration; detect; maximum; depth; layered; fiber; directs; incoming; transmits; signal; respective; optical method; detector output; light reflected; light scattered; ceramic components; ceramic component; laser beam; optical fiber; digital image; tunable laser; apparatus detects; load conditions; ceramic coatings; image processing; approach allows; ceramic coating; microstructural changes; detector outputs; scattering surface; translucent material; structural changes; crack detection; /356/

Citation Formats

Ellingson, William A., Todd, Judith A., and Sun, Jiangang. Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings. United States: N. p., 2001. Web.
Ellingson, William A., Todd, Judith A., & Sun, Jiangang. Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings. United States.
Ellingson, William A., Todd, Judith A., and Sun, Jiangang. Mon . "Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings". United States. https://www.osti.gov/servlets/purl/873971.
@article{osti_873971,
title = {Optical method and apparatus for detection of defects and microstructural changes in ceramics and ceramic coatings},
author = {Ellingson, William A. and Todd, Judith A. and Sun, Jiangang},
abstractNote = {Apparatus detects defects and microstructural changes in hard translucent materials such as ceramic bulk compositions and ceramic coatings such as after use under load conditions. The beam from a tunable laser is directed onto the sample under study and light reflected by the sample is directed to two detectors, with light scattered with a small scatter angle directed to a first detector and light scattered with a larger scatter angle directed to a second detector for monitoring the scattering surface. The sum and ratio of the two detector outputs respectively provide a gray-scale, or "sum" image, and an indication of the lateral spread of the subsurface scatter, or "ratio" image. This two detector system allows for very high speed crack detection for on-line, real-time inspection of damage in ceramic components. Statistical image processing using a digital image processing approach allows for the quantative discrimination of the presence and distribution of small flaws in a sample while improving detection reliability. The tunable laser allows for the penetration of the sample to detect defects from the sample's surface to the laser's maximum depth of penetration. A layered optical fiber directs the incoming laser beam to the sample and transmits each scattered signal to a respective one of the two detectors.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}

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