Electron channeling pattern of ceramic platelets

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb04624.x· OSTI ID:6889088

Pezzotti, G; Sakai, Mototsugu ^[1]; Aoyagi, Eiji ^[2]; Suzuki, Toshiko ^[3]

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1. Toyohashi Univ. of Technology (Japan). Dept. of Materials Science
2. Tohoku Univ., Sendai (Japan). Inst. for Materials Research
3. Topcon Co., Ltd., Tokyo (Japan)

Electron channeling patterns (ECPs), also known as pseudo-Kikuchi patterns, have been imaged in the scanning electron microscope (SEM) according to a contrast mechanism related to the variation in the signal which results from changes in the angle between the incident beam and the crystal lattice of the specimen. It has been shown that this effect makes it possible to determine systematically the crystalline orientation and symmetry of the sample, and that features of the lattice such as tilt, grain boundaries, and, in some cases, individual defects can be imaged and analyzed. Here, ECPs have been generated in the scanning electron microscope from hexagonal-close-packed ceramic (tungsten carbide and silicon carbide) single crystals extracted from commercially available powders. The crystals, commonly employed as reinforcing phases in ceramic composites, were typically platelet-shaped with smooth surfaces. Their averaged diameter was 25 [mu]m with a thickness ranging between 3 and 7 [mu]m. After theoretical maps for the selected crystallographic poles were constructed with a procedure similar to that used for convergent beam electron diffraction, the experimental patterns were indexed and the crystallographic orientation of the crystals was determined. Specific applications for ceramic materials are discussed in comparison with previous work dealing with metals and, as an example of the application of the ECP method, the cleavage plane of fracture has been determined for the SiC platelet embedded in a Si[sub 3]N[sub 4] matrix.

• OSTI ID: 6889088
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:9; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
FRACTURE PROPERTIES
SILICON CARBIDES
CRYSTALLOGRAPHY
ELECTRON CHANNELING
SILICON NITRIDES
TUNGSTEN CARBIDES
DIAGNOSTIC TECHNIQUES
EXPERIMENTAL DATA
HCP LATTICES
CARBIDES
CARBON COMPOUNDS
CHANNELING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
HEXAGONAL LATTICES
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
PNICTIDES
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360603 - Materials- Properties
360206 - Ceramics
Cermets
& Refractories- Radiation Effects
360605 - Materials- Radiation Effects