Stressed oxidation behaviors of 2D C/SiC-BC_x composite under wet oxygen atmosphere

To estimate the capability of SiC-BCx protecting carbon fibers under tensile stress, the creep behavior of 2D C/SiC-BCx Ceramic-matrix composites (CMCs) prepared by chemical vapor infiltration (CVI) has been tested and investigated in static wet oxygen atmosphere at 900 °C. Environmental degradation and Micro-mechanics of the composite was discussed according to the Microstructural analysis observed by scanning electron microscopy (SEM) and length change recorded by Instron material testing device. It is found the room temperature residual flexural strength increases with increasing creep stress. The strength improvement is attributed to the glass phase generation and local stress redistribution. The oxidative damage of 2D C/SiC-BC_x composite is more and more serious with the increase of the creep stress. The steady creep speed and accelerated creep speed lay on the oxidation speed of carbon fiber. The oxidation of BC_x layer and carbon fiber is controlled by gas diffusion.