材料概论课件

OverviewofComposites《材料概论》AnIntroductiontoMaterials7.1AnOverviewofComposites7.1.1IntroductionIthasbeenestimatedthatin1979thecompositeindustryusedasufficientquantityofresins,reinforcingagents,andfillerstoproduce8billionpoundsofcomposites.fiberglassreinforcementasbestos石棉reinforcementotherreinforcements(cellulosicfiber,cotton,polyamide(nylon),andsisal)Thehistoryofcompositesincetheearly1940’s,atwhichtimethehigh-structural-strengthRPweredeveloped.(WorldWarⅡ)19411942combedandcardedcottonfibersimpregnatedwithphenolicresincuredat2000poundspersquareinch(psi)low-pressure-curingpolyester-resinsystemsweredevelopedfiberglass-reinforcedplastics(FRP)hadbeenusedsuccessfullyinstructuralapplications.1945TheapplicationofcompositeFollowingdemobilization,RPbasedonavarietyofreinforcingagentsandresinsgraduallyenteredcivilianlifeasamaterialusedinthemanufactureofboats,cars,appliancehousings,trays,storagecontainers,andotheritems.boatscarsTheapplicationofcompositeSpacecraftandareocraftTheapplicationofcompositeTheapplicationofcompositeroofprofiletoiletappliancehousingsTheapplicationofcompositestoragecontainersandpipesTheapplicationofcompositeTheapplicationofcompositeThegrowthofcompositeAverageconsumptionofcompositeperperson(kg)01234567U.S.EuropeAsiaJapanTheDefinitionofcomposite1.Itismanufactured.(人造)Acompositeisacombinedmaterialcreatedbythesyntheticassemblyoftwoormorecomponentsaselectedfillerorreinforcingagentandacompatiblematrixbinder(i.e.,aresin)inordertoobtainspecificcharacteristicsandproperties.2.Itconsistsoftwoormorephysicallyand/orchemicallydistinct,suitablyarrangedordistributedphaseswithaninterfaceseparatingthem.(两种或两种以上的物理、化学性质不同的物质组成)Thecomponentsofacompositedonotdissolveorotherwisemergecompletelyintoeachother,butneverthelessdoactinconcert.3.Ithascharacteristicsthatarenotdepictedbyanyofthecomponentsinisolation.(单一材料不具备的功能)composite(复合材料)=reinforcement(增强材料)+matrix(基体)example骨头bonecollagen胶原质apatite磷灰石玻璃钢FRPfiberglass玻璃resin树脂混凝土concretesand沙cement水泥TheClassificationofcompositeonthebasisoftheformoftheirstructuralcomponents(thereinforcingagent)fibrous(composedoffibersinamatrix)laminar(composedoflayersofmaterials)(composedofparticlesinamatrix)particulateflakeskeletalPMCpolymermatrixcompositeMatrix:polymerReinforcement:glass,carbonMMCmetalmatrixcompositeMatrix:metal(aluminum)Reinforcement:SiCceramicmatrixcompositeMatrix:ceramicReinforcement:SiC,Boron(硼)inshortfiberorwhiskerstyleCMCTheClassificationofcompositeonthebasisoftheMatrixTheMaterialsofMatrix(PMC)thermosetchangingintoasubstantiallyinfusibleandinsolublematerialwhencuredbytheapplicationofheatorbychemicalmeansthermoplasticcapableofbeingrepeatedlyhardenedandsoftenedbyincreasesanddecreases,respectively,intemperaturephenolicpolyesterepoxypolyimideABSpolypropyleneacrylicpolyethyleneTheMaterialsofConstructionfiberglasscarbonboronglass,paper(cellulosicfiber),cotton,polyamide(聚酰胺)andothernaturalfibers,asbestos(石棉),sisal(剑麻),andjute(黄麻).Specialtyagentsincludecarbon,graphite,boron,steel,andwhiskersTheMaterialsofConstructionSteelfiberwhiskerkevlarfiberTheMaterialsofConstructionTheMaterialsofFillersReinforcingfillersusedinlargequantitiesincludealuminapowder(aluminumoxide),asbestos,calciumcarbonate,calciumsilicate,celluloseflock,cotton(differentforms),fiberglass,glassbeadsandspheres,granite,ironoxidepowder,mica云母,quartz石英,sisal剑麻,siliconcarbide,titaniumoxide,andtungsten钨carbide.TheAdvantageanddisadvantagesofFillersAdvantage:increasedstrengthandstiffness,heatresistance,heatconductivity,stability,wetstrength,fabricationmobility,viscosity,abrasionresistance,andimpactstrength;reducedcost,shrinkage,exothermicheat,thermal-expansion,coefficient,porosity,andcrazing;andimprovedsurfaceappearance.Disadvantage:Theymaylimitthemethodoffabrication,inhibitcuringofcertainresins,andshortenthepotlifeoftheresin.7.2.SurfaceTreatmentofReinforcingMaterialsPurpose:Surfacetreatmentisdonetoimprovetheadhesionoffillersandfiberstomatrixresinbymodifyingthesurfaceofthesolid.改善增强材料的表面，增加与基体的结合Methods:chemical,plasma,coronadischargeandflametreatments化学、等离子、电晕放电、火焰等A.GlassFibers&inorganicfillersCouplingagent(偶联剂)——同时与基体和增强材料(Acompoundwithdualproperty)Inordertoimproveadhesionattheinterface,compoundswithdualproperty,i.e.moleculeshavingchemicalfunctionalitiessimilartothefiberandthematrixresin,areusedFunctionadhesionpromotionprotectingfibersurfacespreventinhibitionofpolymerizationbythesolidsurfaceTheUsageofCouplingAgentAtypicalloadinglevelofcouplingagentrangesfromasmallfractionofapercenttoafewpercentbasedontheweightofthefiberorfiller.Thecouplingagentmaybeaddedtothefillerasaneatliquid,anorganicsolution(有机溶液）,oranaqueoussolution(水溶液）.硅烷偶联剂：结构特征硅烷偶联剂是一类分子中同时含有两种不同化学性质基团(有机官能基团和可水解基团)的硅烷,其经典产物可用通式(ＹＲ)ｎＳｉＸ4-ｎ表示(ｎ=1,2)。式中ＹＲ为非水解有机基团,Ｙ包括链烯基以及末端带有官能团的烃基;Ｘ为可进行水解反应并生成Ｓｉ—ＯＨ的基团,能够与无机材料发生化学反应,或吸附在材料表面,从而提高与无机材料的亲和性。Ｘ、Ｙ为两类反应特性不同的活性基团,其中Ｘ易与无机物或矿物质如玻璃、硅石、陶土、粘土、滑石、二氧化钛和一些金属如铝、钛、硅、铁、铜、锌等的键合能力。而Ｙ则易与有机物中的树脂、橡胶等产物有良好的结合。正是由于硅烷偶联剂分子中间进存在亲有机和亲无机的两种功能团,可以把两种不同化学结构类型和亲和力相差很大的材料在界面连接起来,增加涂料和无机底层及颜料,填料与树脂基料间的结合。硅烷偶联剂的作用过程提出了四步反应模型,即(1)与硅相