Oxidation resistance and oxidation mechanism of SiC_f/SiC-Ti₃SiC₂composites

In this work, a mechanical model was first established to evaluate the effect of Ti₃SiC₂modification on the properties of SiC_f/SiC composites. Subsequently, Ti₃SiC₂-modified SiC_f/SiC (SiC_f/SiC-Ti₃SiC₂) composites were fabricated by the combination technique of chemical vapor infiltration and slurry-assisted polymer impregnation and pyrolysis. After Ti₃SiC₂modification, the flexural strength of SiC_f/SiC composites increased by 17.8 %. The oxidation behavior of SiC_f/SiC-Ti₃SiC₂composites at 800–1350 °C was investigated. With the increasing oxidizing temperature, the weight gain rate of SiC_f/SiC-Ti₃SiC₂composites increased. Compared with SiC_f/SiC composites, SiC_f/SiC-Ti₃SiC₂composites showed the better oxidation self-healing property above 1000 °C. The strength retention ratios of SiC_f/SiC-Ti₃SiC₂composites reached to above 100 % after oxidation at 1200 °C and 1350 °C for 50 h, inferring the superior oxidation resistance. The preferential oxidation of Ti₃SiC₂phase promoted the rapid healing of matrix cracks, preventing the oxidative damage of interphase and the performance degradation of composites.