Tensile creep properties of 2D-SiC_f/SiC composites reinforced with low-oxygen high-carbon type SiC fibers were studied in vacuum at 1300°C∼1430°C. The fracture morphology was observed by scanning electron microscopy and the damage of fiber in 2D-SiC_f/SiC composites was characterized by nanoindentation. Moreover, the microstructure of the composite was investigated by high-resolution transmission electron microscopy. The results show that rupture time is much shortened and steady-state creep rate increase three orders of magnitude when creep temperature is higher than 1400°C. There are two different creep damage mechanisms due to the decrease of interfacial bonding strength at high temperature. The amorphous SiO_xC_y phase in the fibers can crystallize into SiC and C and the SiC grain grows in the fiber. The microstructural changes lead to the decrease of fiber strength and degrade the creep properties of the composite above 1400°C.

研究了低氧高碳型SiC纤维增强的2D-SiC _f / SiC复合材料的拉伸蠕变性能，其工作温度为1300°C〜1430°C。通过扫描电子显微镜观察断裂形态，并通过纳米压痕表征2D-SiC _f / SiC复合材料中纤维的损伤。此外，通过高分辨率透射电子显微镜研究了复合材料的微观结构。结果表明，当蠕变温度高于1400°C时，破裂时间大大缩短，稳态蠕变速率提高了三个数量级。由于高温下界面粘结强度的降低，存在两种不同的蠕变损伤机理。非晶SiO _x C _y纤维中的相会结晶成SiC和C，并且SiC晶粒会在纤维中生长。微观结构变化导致纤维强度降低，并降低了1400°C以上复合材料的蠕变性能。