Characterization and modeling of tensile properties of continuous fiber reinforced C/C-SiC composite at high temperatures

In order to study the effects of temperature on the material behavior of Liquid Silicon Infiltration (LSI) based continuous carbon fiber reinforced silicon carbide (C/C-SiC), the mechanical properties at room temperature (RT) in in-plane and out-of-plane directions are summarized and the tensile properties of C/C-SiC were then determined at high temperature (HT) 1200 degrees C and 1400 degrees C under quasi static and compliance loading. The stressstrain response of both HT tests is similar and almost no permanent strain can be observed compared to the RT, which can be explained through the relaxation of residual thermal stresses and the crack distribution under various states. The different fracture mechanisms are confirmed by the analysis of fracture surface. Furthermore, based on the analysis of hysteresis measurements at RT, a modeling approach for the prediction of material behavior at HT has been developed and a good agreement between test and modeling results can be observed.