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主要研究无界面层、裂解碳和氮化硼3种界面层体系对SiCf/SiC复合材料力学性能的影响:首先,三维四向编织的SiC纤维预制体分别经过无界面层处理、裂解碳界面层制备(CVI工艺)和BN界面层制备(PIP工艺)3种不同工艺处理;以聚碳硅烷为原料,采用PIP工艺制备出3种SiCf/SiC陶瓷基复合材料工艺试验件;对工艺试验件的基本力学性进行研究,评价不同纤维预制体处理工艺对材料性能的影响。研究结果表明,无涂层复合材料样品的弯曲强度最高;具有PyC涂层复合材料的弯曲强度略有下降,但断裂韧性较高;具有BN界面层的复合材料弯曲强度和断裂韧性均出现了较大程度的降低。3个样品力学性能的差别主要与纤维/界面层/基体之间作用力有关。本研究结果可以用于SiCf/SiC复合材料构件制造工作中,为制造工艺的初步筛选提供参考依据。
The effects of three interfacial layer systems without interfacial layer, pyrolytic carbon and boron nitride on the mechanical properties of SiCf / SiC composites were studied. Firstly, the three-dimensional and four-directional braided SiC fiber preforms were treated with no interfacial layer and cracked carbon interfacial layer (CVI process) and BN interfacial layer preparation (PIP process). Three kinds of SiCf / SiC ceramic matrix composite process test pieces were prepared by PIP process using polycarbosilane as raw material. Basic mechanical properties were studied to evaluate the different fiber preform treatment process on the material properties. The results show that the flexural strength of uncoated composites is the highest, the flexural strength of PyC coated composites decreases slightly but the fracture toughness is higher, and the flexural strength and fracture toughness of the composite with BN interlayers are all higher To a large extent reduce. The difference of the mechanical properties of the three samples is mainly related to the force between the fiber / interface layer / substrate. The results of this study can be used in the manufacture of SiCf / SiC composite components, providing a reference for the preliminary screening of the manufacturing process.