(中南大学 粉末冶金国家重点实验室, 长沙 410083)
摘 要: 以炭纤维针刺毡为预制体， 采用化学气相沉积法(CVI)和结合液相浸渍树脂或沥青法制备了热解炭为粗糙层与光滑层结构的准三维C/C复合材料, 并研究了这些材料在0.6 MPa的模拟刹车压力下的摩擦磨损性能与磨损机理。 研究表明： 基体炭为粗糙层热解炭与树脂炭的C/C复合材料摩擦表面能形成较厚且连续的自润滑摩擦膜， 摩擦稳定性最好， 摩擦因数适中， 氧化磨损小， 磨损机理主要为膜的部分脱落、 氧化磨损与相对较小的磨粒磨损； 基体炭为光滑层热解炭与树脂炭或沥青炭的C/C复合材料摩擦表面形成的摩擦膜较薄且不连续， 摩擦稳定性差， 摩擦磨损较大， 磨损机制主要为膜的部分脱落、 磨粒磨损与更严重的氧化磨损； 随着密度的升高， C/C复合材料摩擦稳定性增加， 摩擦因数增加， 磨损降低； 基体炭为单一沥青炭的C/C复合材料， 由于没有热解炭对纤维的保护， 纤维断裂多， 线性磨损尤其大， 磨损机理主要为大量的磨粒磨损与氧化磨损。
关键字: C/C复合材料； 基体炭； 摩擦磨损性能； 磨损机制
（ State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract: The quasi-3D C/C composites with rough laminar (RL) and smooth laminar(SL) pytolytic carbon were fabricated by needled felt through CVI and impregnation with liquid pitch and resin, and their friction and wear properties under braking pressure of 0.6 MPa and worn mechanism were studied. The results show that C/C composites by resin impregnation after CVD with RL have the most stable friction properties and appropriate friction coefficient and low oxidation loss, because the friction surfaces have relatively thick and uniform lubricant friction film and the wear mechanisms are the falling off of part friction film and oxidation wear loss and relatively slight abrasion wear; C/C composites by resin or pitch impregnation after CVD with SL have unstable friction and wear properties and higher wear loss owing to the thin and discontinuous friction film, and the wear mechanisms are also the falling off of part friction film and abrasion wear and larger oxidation wear loss. The higher the density, the more stable the braking curve, and the higher the friction coefficient and the lower the wear rates. Without the protection of pyrolytic carbon, C/C composites by pitch impregnation only have the highest dimension wear rates due to the largely fracture of fibers and the wear mechanism are mainly abrasion wear and oxidation wear.
Key words: C/C composites; matrix carbon; friction and wear properties; worn mechanism
