Abstract
The longitudinal primary creep of long-fiber composites is modeled by considering the transient stress states arising from load transfer from the weaker matrix phase to the stronger fiber phase as the composite transitions from the elastic state present immediately after loading to steady-state stage where both phases creep. The effect of primary creep of each of the phases on the primary creep of the composite is also taken into account. The model is evaluated for the NiA1-W system for which the primary creep of tungsten fibers is quite significant. The composite primary creep strain is predicted to be significant at high applied composite stresses and for high fiber volume fractions and primary creep time is found to be uniquely related to the composite steady-state creep rate. The model is verified with 1025°C compressive creep experiments in the NiA1-W composite system. Good agreement between model predictions and experiments is obtained when the observed composite steady-state creep behavior converges to the steady-state predicted for materials in which both phases experience creep deformation.
Original language | English (US) |
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Pages (from-to) | 4275-4282 |
Number of pages | 8 |
Journal | Acta Materialia |
Volume | 47 |
Issue number | 17 |
DOIs | |
State | Published - Nov 26 1999 |
Funding
This work was supported by the National Science Foundation through grant MSS 9201843, monitored by B. McDonald. T.A.V. and D.C.D. acknowledge the financial support of the Department of Materials Science and Engineering at MIT in the form of teaching assistanships and the AMAX career development chair, respectively. T.A.V. also acknowledges S. Suresh for funding in the form of a post-doctoral position at MIT during which time the preparation of this manuscript was completed.
Keywords
- Composites
- Creep
- Fibers
- High temperature
- Intermetallics
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys