Characterization of microstructure and crack propagation in alumina using orientation imaging microscopy (OIM)

Conference · Sun Dec 01 04:00:00 EST 1996

DOI:https://doi.org/10.2172/443200· OSTI ID:419961

Glass, S J; Michael, J R ^[1]; Readey, M J ^[2]; Wright, S I; Field, D P ^[3]

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1. Sandia National Labs., Albuquerque, NM (United States)
2. Caterpillar, Inc., Peoria, IL (United States)
3. TSL Inc., Provo, UT (United States)

TEM, while capable of determining misorientation of adjacent grains, can practicably provide information only for a small number of grain boundaries. A more complete description of the structure of a polycrystal can be obtained using a new technique OIM, which uses crystallographic orientation data obtained from Backscattered Electron Kikuchi patterns (BEKP), collected using SEM. This paper describes general OIM results for 99.7 and 99.99% Al{sub 2}O{sub 3} samples with grain sizes 4-27 {mu}m. The results include image quality maps, grain boundary maps, pole figures, and lattice misorientations depicted on MacKenzie plots and in Rodrigues space. High quality BEKPs were obtained from all specimens. Images and data readily reveal the grain morphology, texture, and grain boundary structure. Subtle differences in texture and grain boundary structure (crystallite lattice misorientations) are observed for the different alumina specimens. Distributions of misorientations for cracked boundaries in alumina are compared to the bulk distribution of boundaries and generally larger misorientations are observed.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Financial Management and Controller, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 419961
• Report Number(s): SAND--96-1019C; CONF-9606237--4; ON: DE97001443
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CRACKS
GRAIN BOUNDARIES
GRAIN ORIENTATION
KIKUCHI LINES
POLYCRYSTALS
SCANNING ELECTRON MICROSCOPY
TEXTURE