Fatigue behavior of 2D C/SiC composites modified with Si-B-C ceramic in static air

In order to investigate fatigue behavior of 2D C/SiC composites modified with Si-B-C ceramic, different kinds of modified specimens were fabricated and fatigued at desired temperatures in static air. Fatigue lifetime and load-displacement hysteresis loop of C/(SiC-SiBC)_m modified with Si-B-C matrix and SBS-C/SiC modified with Si-B-C coating were analyzed after fatigue respectively. Results show that Si-B-C ceramic can improve obviously fatigue lifetime of C/SiC composites in static air. Meanwhile, fatigue lifetime of sample modified with Si-B-C coating is superior to that of Si-B-C matrix. Quantity and formation rate of borosilicate glass formed from Si-B-C ceramic directly affect crack-healing and fatigue lifetime of specimens. Oxidation damage dominates for the specimens, and damage caused by fatigue stress accelerates the oxidation damage during fatigue process. The damage is controlled by oxidation of carbonaceous material under 1000 °C, and oxidant diffusion from borosilicate glass above 1000 °C.