C/C复合材料微观结构对其制动摩擦磨损性能的影响

采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)等手段研究了基体炭分别为树脂炭和粗糙层热解炭结构的C/C复合材料的微观结构,并探讨了材料的微结构对其制动摩擦磨损性能的影响.结果表明:炭纤维附近的树脂炭被高度石墨化,导致树脂炭样件具有适当、稳定的摩擦系数;树脂炭片层之间存在明显的裂纹,远离炭纤维的树脂炭仍是各向同性结构,容易被剪切力剪断,产生大量碎屑,破坏了摩擦动态平衡,磨损量大是制约其作为优良制动摩擦材料的关键因素.

Effects of Microstructure on the Frictional Properties of C/C Composites

Microstructure of C/C composites with resin-derived carbon and rough laminate pyrocarbon was studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM). And effect of microstructure on frictional properties was discussed. TEM and SAED results showed that the resin-derived carbon near the carbon fibers was highly graphitized, which conferred appropriate and stable friction coefficient on composites. Because of the visible cracks between resin-derived carbon lamellae and the isotropical carbon beyond the carbon fiber, resin-derived carbon was readily destroyed by shearing. This gave a birth of a large number of chippings and disturbed the dynamic equilibrium . The high wear rate of the composites was the main problem for the application as a braking disc.