Preparation And Friction Properties Of Vascular Self-Lubricating Carbon Fiber/Polymer Composites

In this thesis,polylactic acid(PLA)fiber is used as sacrificial components,carbon fiber(CF)is used as reinforcing components,both of which were woven into polylactide fiber-carbon fiber(PLA-CF)composite fiber fabric by the measure of warp and weft weave.By pour casting,vaporization of sacrificial components(VaSC)technology and vacuum oil immersion,methyl silicone oil was infiltered into the vascular networks and vascular self-lubricated composites or carbon fiber reinforced vascular self-lubricated composites was prepared.The relationship between vascular density,carbon fiber(CF)content and tribological properties/mechanical properties of composites was studied,and the mechanism of vascular lubrication was analyzed.The results demonstrate that:For vascular self-lubricated composites,the released lubricating oil from the worn-out of the shell material during the friction could form a lubricating film between the friction pair.With the increase of radial direction vascular density,the tribological properties of the vascular self-lubricating composites were improved.When the radial direction vascular density is 8 pores/lOmm,the tribological performance of vascular self-lubricating polyurethane(8VAPU)and vascular self-lubricating epoxy resin(8VAEP)tends to be stable.Compared with pure PU?the average friction coefficient and volume wear rate of 8VAPU are reduced by 88.51%and 82.22%,respectively.The average friction coefficient and volume wear rate of 8VAEP are reduced by 67.95%and 85.71%,respectively.When the radial direction vascular density is 10 pores/10 mm,the tribological properties of the vascular self-lubricating silicone resin(10VASI)tend to be stable.Compared with the pure SI,the average friction coefficient and volume wear rate of VASI 10 are reduced by 77.69%and 78.40%,respectively.However,the existence of vascular structure weakens the strength of the matrix,resulting in a decrease in the mechanical properties(strength and modulus)of the composites.Carbon fiber reinforced vascular self-lubricated composites which demonstrate improved tribological and comparable mechanical properties compared with pure resin were fabricated by adopting PLA-CF composite fiber fabric.Compared with pure EP,the friction coefficient and wear rate of 8CF/8VAEP are reduced by 51.28%and 81.14%.Meanwhile,the tensile strength and bending strength of the composite were increased by 23.49%and 126.22%,respectively.For the 8CF/10VASI composites,the friction coefficient and wear rate are reduced by 77.48%and 78.40%,respectively,while the tensile strength of the composite increased by 63.91%.Carbon fiber reinforced vascular self-lubricated composites exhibited excellent self-lubricating properties and high mechanical properties.The excellent self-lubricating properties arise from the lubrication mechanism transformation from dry friction to boundary lubrication due to the released lubricating oil.Carbon fiber with high strength and modulus could effectively disperse stress and correspondingly improve the mechanical properties of the composites.