添加BN对光滑层热解炭结构的C/C复合材料摩擦性能的影响

通过粉末层铺法向全网胎炭纤维预制体中添加六方氮化硼粉末和化学气相沉积热解炭增密制备C/C-BN复合材料。在MM 1000摩擦试验机上对其摩擦磨损性能进行测试,并对摩擦表面进行光学形貌观察以及对材料的组织结构和磨屑进行SEM形貌观察。结果表明:与C/C复合材料相比,C/C-BN复合材料的线性磨损率降低了40%,质量磨损率降低了70%;摩擦表面中的六方BN在摩擦过程中始终保持稳定,BN的存在使光滑层热解炭结构的C/C复合材料的摩擦因数曲线变得平稳、波动小并且对刹车压力响应迅速,摩擦表面上形成了一层薄的摩擦膜。

Effect of BN on tribological properties of C/C composites with SL pyrolytic carbon texture

The carbon fiber reinforced/carbon-boron nitride(C/C-BN) hybrid matrix composites were prepared by adding hexagonal boron nitride(h-BN) powders in preform and subsequent chemical vapor infiltration(CVI) process.Friction and wear properties of C/C-BN were investigated on an MM-1000 testing machine.The morphologies of wear surfaces were observed by optical microscope.The morphologies of wear debris and the microstructures of samples were analyzed by scanning electron microscope.The results show that the C/C-BN composites display linear wear rate 40% lower and mass wear loss 70% lower than those of C/C composites.The h-BN in the matrix always keeps stable.The addition of BN in the matrix can effectively improve the stability of friction curves of C/C composites with a SL pyrolytic carbon texture,and cause the formation of a thin wear film on the wear surface.