Abstract
In many potential applications, continuous fiber-reinforced ceramic matrix composites (CFCMCs) will encounter cyclic fatigue loadings at high frequencies (25 Hz or higher). While most of the work in the area of fatigue of CFCMCs has concentrated on low frequency behavior, high frequency behavior is equally important. In CFCMCs, stress-strain hysteresis occurs during fatigue and is associated with energy dissipation in the composite. In addition to this, the repeated friction and sliding between fiber and matrix are responsible for a substantial temperature rise at the fiber/matrix interface. In this study, [0/90] and [±45] SCS-6 (silicon carbide)/Si3N4 composites made by hot pressing were investigated under high frequency fatigue loadings. The angle-ply laminate showed the same extent of heating as cross-ply laminates, but at much lower stress levels. Frictional heating was caused by sliding at the fiber/matrix interface. Temperature rise due to heat generation in the specimens correlated very well with damage in modulus as a function of fatigue cycles in the composites. Matrix microcracking was more predominant in the angle ply than in the cross-ply composite, due to the much lower stiffness of the angle-ply composite in the longitudinal loading direction.
Original language | English (US) |
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Pages (from-to) | 2423-2427 |
Number of pages | 5 |
Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
Volume | 28 |
Issue number | 11 |
DOIs | |
State | Published - Jan 1 1997 |
Externally published | Yes |
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys