Research On Preparation And Tribological Properties Of Carbon Fiber Phenolic Resin-based Composites

Carbon fiber friction materials possess a series of excellent character, which contain self-lubricating, wear-resisting, corrosion resistance, vibration-absorption, unpitched sound-reducing, lower relative density, higher specific strength and process simply and so on. This advantages not only can solve many technical question that some metallic material could not overcome as to increase the machinery equipment operational reliability, but also improve the technical parameters of equipment, which will save vast precious metal, alleviate the weight of machinery equipment and reduce fabricating cost totality. Then, Carbon fiber friction materials have been turn into a new type friction materials On twenty-first Century.In this paper, the surface modification of PAN-based carbon fiber is using the concentrated nitric acid and silane coupling agent (KH550), With phenolic resin as matrix and graphite, PEEK powder as friction performance conditioning agent, applying the thermo-compression formation craft to produce composite material. The structure and surface properties of carbon fiber were investigated by SEM, FTIR, XPS. The tensile testing machine and Multifunctional vertical friction wear tester (MVF-IA) was used to test the composite material tensile strength and frictional wear respectively.The results showed that, the surface treatment that used concentrated nitric acid and silane coupling agen can increase the surface roughness and chemical activity of carbon fiber and improve the interface bonding between carbon and resin matrix, thus enhanced the tensile strength and reduced the wear rate of composite material. After the surface treatment, the tensile strength, friction coefficient and wear rate of composite material is 85.79MPa,0.18 and 3.056×10-6g(N·m)-1 respectively.The friction coefficient and wear rate of composite material will decrease after mixing graphite into matrix. When the addition of graphite is 15 wt%, the friction coefficient and wear rate of material will be equal to 0.1 and 0.37×10-6g(N·m)-1 respectively,the composite material shows speed and contact pressure stability of tribology performance.The friction coefficient will increase and the wear rate of will decrease after mixing PEEK powder. When the addition of PEEK powder is 10 wt%, the friction coefficient and wear rate of material will be equal to 0.28 and 0.96 X 10-6g(N · m)-1 respectively, the friction coefficient is most steady. When the addition of PEEK powder add to 15wt%, the friction coefficient will increase to 0.35, the friction coefficient fluctuation will be obvious and not be steady. the composite material shows speed and contact pressure stability of tribology performance in a higher load pressure.