为了研究制备工艺对三维针刺C/SiC复合材料(3N-C/SiC)层向压缩力学性能的影响,对分别采用反应熔体浸渍( RMI)和化学气相浸渍( CVI)2种工艺制备的3N-C/SiC进行了不同应变率下压缩性能研究,并对比了2种工艺试样在破坏前后的显微结构。结果表明,在高应变率下2种工艺试样的破坏强度分布均遵循Weibull分布,且RMI工艺试样的性能稳定性明显高于CVI工艺试样。2种工艺试样的压缩强度均具有明显的应变率强化效应,且与对数应变率近似呈线性关系。观察断口形貌发现,在静态压缩载荷作用下,2种工艺试样的破坏方式为剪切破坏和分层破坏的叠加,而在动态压缩条件下试样的破坏方式为劈裂破坏。研究发现,CVI工艺试样纤维束断口不平整；RMI工艺试样断口相对平整,纤维束多发生整束剪断,且动态条件下纤维束的束内脱粘现象得到明显的抑制。%In order to study the effect of different preparation processes on compressive mechanical properties, the compressive properties of 3N-C/SiC composites prepared by reaction melt impregnation ( RMI) and chemical vapor impregnation ( CVI) were in-vestigated respectively at various strain rates, and compared the microstructure of the samples before and after failure. The results show that the failure strength of the two kinds of composite under high strain rate all obeys Weibull distribution, and RMI compos-ites have a higher stability than the CVI composites. Both composites present an obvious strengthening effect on strain rate, mean-while, the relationship between failure strength and logarithmic strain rate characterizes linear. According to the fracture morpholo-gy, the mixture of shear failure and delaminated failure leads to the failure under quasi-static compression, on the contrary, the failure mode of the composites under dynamic compression is splitting failure. In addition, fracture of the samples with RMI process is smoother than the samples with CVI. The phenomenon of debonding within bundle is inhibited obviously under dynamic loading for the samples with RMI process.
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