Effect of Temperature on Creep Rate of Three-Dimensional C/SiC Composites

The creep behavior of three-dimensional(3D)C/SiC composites was examined at 1 300℃ and 1 500℃ using vacuum high-temperature creep testing machine.The effect of temperature on the creep rate of the composites was also investigated.Microstructure of the composites before and after creep testing was analyzed by means of SEM and TEM.The results indicate that the creep curves of 3D C/SiC composites were composed of two stages including deceleration creep stage and steady state creep stage,and no accelerated creep stage was observed until the fracture of the specimens.With the increase of temperature,the interfacial sliding resistance decreased due to the increase of the thickness of highly oriented lamellar graphite transformed from turbostratic graphite in the pyrolytic carbon interphase near the SiC matrix,resulting in a more rapid creep rate of 3D C/SiC composites.