Abstract
Fiber fractures are crucial in initiating damage zones that ultimately determine the strength and lifetime of fiber-reinforced metal matrix composites. The evolution of damage in a metal matrix composite (MMC) comprised of a row of unidirectional SiC fibers (32 vol pct) surrounded by a Ti matrix was examined, for the first time, using X-ray microdiffraction. Multiple strain maps including both phases were collected in situ under applied tensile stress. The elastic axial strains were then compared to predictions from a modified shear-lag model, which, unlike other shear-lag models, considers the elastic response of both constituents. The strains showed good correlation with the model. The results confirmed, for the first time, both the need and validity of this new model specifically developed for large scale multifracture simulations of MMCS. The results also provided unprecedented insight for the model, revealing the necessity of incorporating such factors as plasticity of the matrix, residual stress in the composite, and selection of the load sharing parameter.
Original language | English |
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Pages (from-to) | 3839-3845 |
Number of pages | 7 |
Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
Volume | 33 |
Issue number | 12 |
DOIs | |
Publication status | Published - Dec 2002 |
Externally published | Yes |
Funding
The authors are grateful to Dr. H. Deve, 3M Corp., for providing the specimens and helpful discussions about the properties of Ti-SiC composites. They also express their sincere gratitude to Dr. I.C. Noyan, IBM Watson Research Center, for the use of his stress fixture. This study was supported by the National Science Foundation (CAREER Grant No. DMR-9985264) at Caltech and a Laboratory-Directed Research and Development Project (No. 2000043) at Los Alamos. The work at the Advanced Photon Source was supported by the United States Department of Energy, Office of Basic Energy Sciences (Contract No. W-31-109-ENG-38).
Funders | Funder number |
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Laboratory-Directed Research and Development Project | 2000043 |
Office of Basic Energy Sciences | |
United States Department of Energy | |
National Science Foundation | DMR-9985264 |
Los Alamos National Laboratory |