纺织材料的英文版系列文00002).ppt

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1、HighPerformanceFibersandFibrousmaterialsYipingQiuDonghuaUniversityOutlineCarbonfibersGlassfibersAramidfibersUltraHighModulusPolyethylenefibersCarbonnanotubesCeramicfibersMechanicalpropertiesoffibersCarbonfibersReadingassignmentHullandClyne,Chapter2FibresandMatrices,AnIn

2、troductiontoCompositeMaterials,2nded.CambridgeUniversityPress.Pages9–30.CarbonfibersManufacturingprocessesStructureandpropertiesCarbonfibersManufacturingprocessesThermaldecompositionoffibrousorganicprecursorsExtrusionofpitchCarbonfibermanufacturingprocessesRayonbasedcar

3、bonfibersStabilizationat400°CinO2,depolymerization&aromatizationCarbonizationat400-700°CinaninertatmosphereStretchandgraphitizationat700-2800°C(improveorientationandincreasecrystallinityby30-50%)CarbonfibermanufacturingprocessesPAN(polyarylonitrile)basedcarbonfibersPANf

4、ibersStabilizationat200-300°CinO2,depolymerization&aromatization,convertingthermoplasticPANtoanonplasticcyclicorladdercompoundCarbonizationat1000-1500°CinaninertatmospheretogetridofnoncarbonelementsStretchandgraphitizationat>1800°C,formationofturbostraticstructureStabil

5、izationofPANfibersPitchbasedcarbonfiberspitch-highmolecularweightbyproductofdistillationofpetroleumheated>350°C,condensationreaction,formationofmesophase(Liquidcrystal):StructureofmesophasepitchmeltspinningintopitchfibersOxidationatatemperaturebelowsofteningtemperaturec

6、onversionintographitefibersat~2000°CwithouttensionPitchbasedcarbonfibersAdvantagesMuchhigherdegreeofgraphitizationthanpolymerbasedcarbonfibersHighstrengthandmodulusHighthermalconductivity:evenmuchbetterthancopperStructureofcarbonfibersTurbostraticstructureFiberstructure

7、CarbonfibersAdvantagesofallcarbonfibersHightensilestrengthandtensilemodulusNonreactiveResistancetocorrosionHighheatresistancehightensilestrengthatelevatedtemperatureLowdensityCarbonfibersDisadvantagesHighcostBrittleOxidationat>400ºCCarbonfibersOtherinterestingproperties

8、LubricatingpropertiesElectricalconductivityThermalconductivityLowtonegativethermalexpansioncoefficientDifferen