Fatigue-crack growth and fracture properties of coarse and fine-grained Ti{sub 3}SiC{sub 2}
An experimental study of fracture and cyclic fatigue-crack growth behavior was made in a reactively hot-pressed monolithic Ti{sub 3}SiC{sub 2} ceramic with both fine (3--10 {mu}m) and coarse-grained (50--200 {mu}m) microstructures. Whereas the fine-grained microstructure exhibited a steady-state (plateau) R-curve fracture toughness of K{sub c} {approximately} 9.5 MPa{radical}m, the coarse-grained Ti{sub 3}SiC{sub 2} exhibited a K{sub c} {approximately}16 MPa{radical}m. The latter value is though to be one of the highest fracture toughnesses ever observed in a monolithic, non-transforming ceramic, consistent with the profusion of crack-bridging processes active in the crack wake. Moreover, fatigue-crack growth thresholds, {Delta}K{sub TH}, were comparatively high for ceramic materials, as indicated by the coarse-grained microstructure which had a threshold {Delta}K{sub TH} of {approximately}9 MPa{radical}m. Such fatigue crack growth was associated with substantial evidence for wear degradation at active bridging sites behind the crack tip.
- Research Organization:
- Univ. of California, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 20050504
- Journal Information:
- Scripta Materialia, Vol. 42, Issue 8; Other Information: PBD: 14 Apr 2000; ISSN 1359-6462
- Country of Publication:
- United States
- Language:
- English
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