Creep-fatigue response of structural ceramics: 1, Comparison of flexure, tension, and compression testing
- Oak Ridge National Lab., TN (United States)
- Norton Co., Northboro, MA (United States)
The stress sensitivities of the creep rates of commercially available Al{sub 2}O{sub 3} and Si{sub 3}N{sub 4} ceramics were measured at elevated temperatures using tension, compression, and flexure specimens. Pronounced differences in creep deformation behavior in compression and tension were observed for both ceramics. These differences were attributed to the generation of a creep-induced damage zone under tensile loading which accelerated the creep rate. The evolution of this damage zone was confirmed by (1) fractographic studies of failed tensile samples and (2) the observed stress-dependence of the creep failure strain. The creep rate-stress data generated fromn the flexure creep testing were found to be in fair agreement with results predicted from a creep deformation model. Differences between experimental and predicted creep behavior were attributed to the failure of the model to account for primary creep. This model was also capable of describing differences in the fatigue-life characteristics of a silicon nitride measured in flexure and tension.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10125897
- Report Number(s):
- CONF-9010201-2; ON: DE92008275
- Resource Relation:
- Conference: 37. Sagamore army materials research conference,Plymouth, MA (United States),1-4 Oct 1990; Other Information: PBD: [1990]
- Country of Publication:
- United States
- Language:
- English
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