单向炭布叠层C/C复合材料的热压法制备及其性能

以经表面处理的石墨、单向炭布、和沥青粉为原料,通过热压烧结制备炭布叠层C/C复合材料.考察了炭布含量对材料密度、孔隙率、弯曲强度以及摩擦磨损的影响,采用MM200摩擦磨损试验机进行了环-块摩擦磨损实验,并借助SEM表征了材料的弯曲断口和磨痕形貌.结果表明:当炭布质量分数为50％时,C/C复合材料的综合性能最好,抗弯强度为112.2MPa,密度为1.72 g/cm3,摩擦系数为0.28,磨损率为3.68×10-13 m3·N-1·m-1.弯曲实验中材料呈“假塑性”方式破坏,断口出现大量纤维的拔出.石墨相含量的增加有利于形成较好的摩擦膜,降低磨损率,保持摩擦系数稳定.

Performance of unidirectional carbon fibre cloth/carbon composite laminates fabricated by hot-pressing

Unidirectional carbon fibre cloth/carbon composite laminates were fabricated by hot-pressing alternating stacks of unidirectional carbon fibre cloth and uniformly-spread powder mixtures of phenolic-resin coated nature graphite flakes and pitch.The effects of the contents of carbon fibre cloth on the density,porosity,flexural strength,friction and wear properties of the composite laminates were investigated by SEM,a friction-and-wear testing machine and a universal testing machine.Results showed that the sample with the best overall performance had a mass fraction of carbon fibre cloth of 50%.This material had a flexural strength of 112.2 MPa,a density of 1.72 g/cm3,a friction coefficient of 0.28,and a wear rate of 3.68×10-13 m3 · N-1 · m-1.Failure behavior was pseudoplastic and there were a large number of fibre pullouts on the fracture surface.An increase of graphite content was favorable for the formation of a film during wear,which reduced the wear rate and resulted in a steady value of the coefficient of friction.