Defect mapping system
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. 20 figures.
- Issue Date:
- OSTI Identifier:
- 35069
- Assignee:
- Midwest Research Inst., Kansas City, MO (United States) CHO; SCA: 420500; PA: EDB-95:065021; SN: 95001365511
- Patent Number(s):
- US 5,406,367/A/
- Application Number:
- PAN: 8-060,301
- Contract Number:
- AC02-83CH10093
- Resource Relation:
- Other Information: PBD: 11 Apr 1995
- Research Org:
- Midwest Research Institute; National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Org:
- USDOE
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; MATERIALS; DEFECTS; MATERIALS TESTING; DETECTION; MAPPING; POLYCRYSTALS; LASER RADIATION; EQUIPMENT; SAMPLE PREPARATION; VISIBLE RADIATION; DATA ANALYSIS; SAMPLE HOLDERS