In-situ observation of crack growth in glassy alumina at 1275 C

Conference · Thu Oct 01 04:00:00 EDT 1992 · Ceramic Engineering and Science Proceedings; (United States)

OSTI ID:7110954

Heinzelmann, M; Ritter, J E; Jakus, K

Crack propagation in an 85 percent alumina was studied in situ at 1275 C as a function of displacement rates from 3 to 50 microns/min using short double cantilever beam (s-DCB) specimens with and without a rear-notch wedge. With the rear-notch wedge, the crack propagated by a creep rupture process that involved the nucleation of microcracks ahead of the main crack tip and the subsequent linkage of these microcracks to the main crack. This creep crack process produced a very tortuous crack path. The linkage of these creep-nucleated microcracks to the main crack gave rise to significant statistical variability in the load-displacement curves. This creep crack growth behavior was found to be dependent on the C-integral, where crack velocity was proportional to C by a power law function. Without the rear notch wedge, creep nucleated microcracking was considerably reduced and crack propagation became more coplanar. 15 refs.

• OSTI ID: 7110954
• Report Number(s): CONF-920144--
• Conference Information: Journal Name: Ceramic Engineering and Science Proceedings; (United States) Journal Volume: 13:9-10
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CRACK PROPAGATION
CREEP
FAILURE MODE ANALYSIS
FAILURES
MECHANICAL PROPERTIES
NOTCHES
OXIDES
OXYGEN COMPOUNDS
RUPTURES
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K