Defect mapping system

Patent · Sun Jan 01 00:00:00 EST 1995

OSTI ID:869832

Sopori, Bhushan L ^[1]

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1. Denver, CO

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.

• Research Organization: Midwest Research Institute, Kansas City, MO (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-83CH10093
• Assignee: Midwest Research Institute (Kansas City, MO)
• Patent Number(s): US 5406367
• OSTI ID: 869832
• Country of Publication: United States
• Language: English

Related Subjects

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/