ABSTRACT

C/C-SiC composites with different SiC content was fabricated by reactive melt infiltration of silicon with four types of porous C/C composites, which are prepared through chemical vapor infiltration. Compared with the high-density C/C composites and silicified graphite, the C/C-SiC composites demonstrated excellent balance of mechanical properties, especially impact toughness. The results show that the porosity of C/C composites is a key factor to affect the SiC content in the C/C-SiC composites. The friction coefficient of the C/C-SiC composites measured by block-on-ring frictional test are mainly influenced and a W18Cr4V steel alloy (hardness 55 ∼ 60HRC) was used as the friction pair material with roughness of 0.8 μm. The friction coefficients are mainly influenced by the SiC content and the test load. It first increases and then decreases as the SiC content and the test load increases, reaching a minimum of 0.011 for 44.22 vol.% SiC composite under 80N. Water also plays an important role in decreasing the friction coefficient. The observations of worn surface and wear debris indicate that the main wear mechanism of C/C-SiC composites is the abrasive wear mechanism.

摘要

采用化学气相渗透法制备的四种类型的多孔C / C复合材料，通过硅的反应性熔渗法制备了不同SiC含量的C / C-SiC复合材料。与高密度C / C复合材料和硅化石墨相比，C / C-SiC复合材料表现出优异的机械性能平衡，尤其是冲击韧性。结果表明，C / C复合材料的孔隙率是影响C / C-SiC复合材料中SiC含量的关键因素。主要通过环上摩擦试验测量的C / C-SiC复合材料的摩擦系数，并且使用W18Cr4V合金钢（硬​​度55〜60HRC）作为粗糙度为0.8μm的摩擦副材料。摩擦系数主要受SiC含量和测试载荷的影响。随着SiC含量的增加和测试负荷的增加，它首先增加，然后减少，在80N下，对于44.22％（体积）的SiC复合材料，最小值达到0.011。水在降低摩擦系数方面也起着重要作用。磨损表面和磨损碎片的观察表明，C / C-SiC复合材料的主要磨损机理是磨料磨损机理。