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Title: Defect mapping system

Abstract

Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities.

Inventors:
 [1]
  1. Denver, CO
Issue Date:
Research Org.:
Midwest Research Institute, Kansas City, MO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
869832
Patent Number(s):
5406367
Assignee:
Midwest Research Institute (Kansas City, MO)
DOE Contract Number:  
AC02-83CH10093
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
defect; mapping; apparatus; detecting; defects; surfaces; polycrystalline; materials; manner; distinguishes; dislocation; pits; grain; boundaries; laser; illuminating; wide; spot; surface; material; light; integrating; sphere; apertures; capturing; scattered; etched; intermediate; range; specular; reflection; allowing; near; pass; optical; detection; devices; measuring; intensities; respective; center; blocking; aperture; filter; screen; reflected; nondefect; portions; x-y; translation; stage; mounting; signal; processing; computer; equipment; accommodate; rastor; recording; displaying; boundary; densities; special; etch; procedure; included; prepares; produce; distinguishable; scattering; patterns; statistical; relevance; optical detection; crystalline materials; translation stage; light scattering; crystalline material; detection device; light scattered; signal processing; grain boundaries; scattered light; material surface; reflected light; polycrystalline material; grain boundary; measuring intensities; detection devices; integrating sphere; dislocation pits; intermediate range; light integrating; signal process; near range; etched grain; wide spot; center block; distinguishes dislocation; mapping defects; /356/

Citation Formats

Sopori, Bhushan L. Defect mapping system. United States: N. p., 1995. Web.
Sopori, Bhushan L. Defect mapping system. United States.
Sopori, Bhushan L. Sun . "Defect mapping system". United States. https://www.osti.gov/servlets/purl/869832.
@article{osti_869832,
title = {Defect mapping system},
author = {Sopori, Bhushan L},
abstractNote = {Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {1}
}

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