Internal Friction of Continuous Fiber-reinforced SiC-matrix Composites

The internal friction of C/SiC and SiC/SiC composites was investigated by means of forced vibration from room temperature to 600℃ under different strain amplitude, and the internal friction mechanism was also discussed. The results show that the internal friction of C/SiC composites decreases at first and then increases with increasing temperature, and the minimum of internal friction occurs at about 120℃. While the internal friction of SiC/SiC composites increases monotonically with the increase of temperature. C/SiC composites have a higher internal friction value and lower dynamic modulus than SiC/SiC composites. The internal friction of both C/SiC and SiC/SiC composites decreases when the strain amplitude is increased, while the dynamic modulus of both the composites is independent of the strain amplitude.