对含有几种典型界面结构和SiC纳米线的CVI-SiC/SiC复合材料的弯曲性能和断裂韧性进行了比较研究. 研究表明: 界面涂层对SiC/SiC的力学性能至关重要, 120nm厚的碳界面涂层使材料的强度与韧性都增加一倍; 在用140nm厚的SiC层将该碳层分为更薄的两层, 形成C/SiC/C多层界面涂层时, 材料的强度没有明显的变化, 而断裂韧性则略有提高. 对基体中弥散分布有SiC纳米线的SiC/SiC的力学性能研究表明, SiC纳米线具有非常高的强化效率, 使SiC/SiC复合材料具有更高的强度和韧性.
The flexural properties and fracture toughness of several CVI-SiC/SiC composites with various fiber/matrix interlayers and SiC nanowires were investigated comparatively. The results indicate that interlayer is very important to the mechanical properties of the composites. A 120nm thick carbon interlayer increases both the strength
and toughness twofold. When the single carbon interlayer is replaced by a C/SiC/C tri-interlayers but with same total amount of carbon, the composite shows no significant changes of the properties. Preliminary study on the composite with SiC nanowires in the matrix shows that SiC nanowires possesses very high reinforcement efficiency, providing the composite high strength and toughness.
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