The effect of single-layer pyrocarbon (PyC) and multilayered (PyC/SiC)_n=4 interphases on the flexural strength of un-coated and SiC seal-coated stitched 2D carbon fiber reinforced silicon carbide (C_f/SiC) composites was investigated. The composites were prepared by I-CVI process. Flexural strength of the composites was measured at 1200 °C in air atmosphere. It was observed that irrespective of the type of interphase, the seal coated samples showed a higher value of flexural strength as compared to the uncoated samples. The flexural strength of 470 ± 12 MPa was observed for the seal coated C_f/SiC composite samples with multilayered interphase. The seal coated samples with single layer PyC interphase showed flexural strength of 370 ± 20 MPa. The fractured surfaces of tested samples were analyzed in detail to study the fracture phenomena. Based on microstructure-property relations, a mechanism has been proposed for the increase of flexural properties of C_f/SiC composites having multilayered interphase.

研究了单层热碳（PyC）和多层（PyC / SiC）_{n = 4}中间相对未涂层和SiC密封涂层缝合的2D碳纤维增强碳化硅（C _f / SiC）复合材料的弯曲强度的影响。复合材料是通过I-CVI工艺制备的。在空气气氛中于1200℃下测量复合材料的弯曲强度。观察到，不管中间相的类型如何，与未涂覆的样品相比，密封涂覆的样品显示出更高的挠曲强度值。密封涂层C _f的弯曲强度为470±12 MPa/ SiC复合样品具有多层相间。具有单层PyC界面的密封涂层样品的弯曲强度为370±20 MPa。详细分析了测试样品的断裂表面，以研究断裂现象。基于微观结构属性关系，一个机构已经提出了对C的弯曲性能的增加_˚F / SiC复合材料具有多层相间。