Grain-boundary sliding measurements in Al[sub 2]O[sub 3] by machine vision photogrammetry

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Materials Science; (United Kingdom)

DOI:https://doi.org/10.1007/BF01124658· OSTI ID:6988638

Blanchard, C R; Page, R A ^[1]

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1. Southwest Research Inst., San Antonio, TX (United States)

The nucleation, growth and coalescence of grain-boundary cavities is the primary damage mechanism observed during creep of structural ceramics. Furthermore, grain-boundary sliding (GBS) has been identified as the driving force process. Although the creep characteristics of structural ceramics have been extensively studied, very little is known about the details of GBS during creep and how GBS relates to cavitation kinetics. This paper presents the results of a study using a machine vision system to measure Mode 2 GBS displacements in a Lucalox Al[sub 2]O[sub 3]. Specifically, sliding displacements as large as 0.4 [mu]m were measured. The measured displacements indicate that some grain boundaries experienced shear strains and strain rates of 4,200% and 2.3 [times] 10[sup [minus]2]s[sup [minus]1], respectively. The techniques utilized for these measurements are described in detail, and data gathered during a 2 1/2 h compressive creep test under a stress of 138 MPa at 1,600 C are presented and discussed.

• OSTI ID: 6988638
• Journal Information: Journal of Materials Science; (United Kingdom), Journal Name: Journal of Materials Science; (United Kingdom) Vol. 26; ISSN JMTSAS; ISSN 0022-2461
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CREEP
DATA
EXPERIMENTAL DATA
GRAIN BOUNDARIES
IMAGES
INFORMATION
MATERIALS TESTING
MEASURING METHODS
MECHANICAL PROPERTIES
MECHANICAL TESTS
MICROSTRUCTURE
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
TESTING