Effects of microstructure on the strength and fatigue behavior of a silicon carbide fiber-reinforced titanium matrix composite and its constituents
- Ohio State Univ., Columbus, OH (United States)
The results of a systematic study of the effects of microstructure on the strength and fatigue behavior of a symmetric [0/90]{sub 2s} Ti-15V-3Cr-3Al-3Sn/SiC (SCS-6) composite are presented along with relevant information on failure mechanisms in the composite constituents, i.e., the interface, fiber, and matrix materials. Damage micromechanisms are elucidated via optical microscopy, scanning electron microscopy (SEM), and nondestructive acoustic emission (AE) and ultrasonic techniques. Composite damage is shown to initiate early under cyclic loading conditions and is dominated by longitudinal and transverse interfacial cracking. Subsequent fatigue damage occurs by matrix slip band formation, matrix and fiber cracking, and crack coalescence, prior to the onset of catastrophic failure. However, the sequence of the damage is different in material annealed above or below the {beta} solvus of the Ti-15-3 matrix material. Mechanistically based micromechanics models are applied to the prediction of the changes in modulus induced by fatigue damage. Idealized fracture mechanics models are also employed in the prediction of the fatigue lives of smooth specimens deformed to failure at room temperature. The article highlights the potential to develop mechanistically based predictive models based on simplified mechanics idealizations of experimental observations.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 540994
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 8 Vol. 28; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
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