CompositesA Vision for the Future.docx

CompositesA Vision for the Future.docx

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CompositesAVisionfortheFuture

Composites:

AVisionfortheFuture

SoumitraBiswas,AtulMittal&GSrikanth

Overthelastthirtyyearscompositematerials,plasticsandceramicshavebeenthedominantemergingmaterials.Thevolumeandnumberofapplicationsofcompositematerialshavegrownsteadily,penetratingandconqueringnewmarketsrelentlessly.Moderncompositematerialsconstituteasignificantproportionoftheengineeredmaterialsmarketrangingfromeverydayproductstosophisticatednicheapplications.

Whilecompositeshavealreadyproventheirworthasweight-savingmaterials,thecurrentchallengeistomakethemcosteffective.Theeffortstoproduceeconomicallyattractivecompositecomponentshaveresultedinseveralinnovativemanufacturingtechniquescurrentlybeingusedinthecompositesindustry.

Itisobvious,especiallyforcomposites,thattheimprovementinmanufacturingtechnologyaloneisnotenoughtoovercomethecosthurdle.Itisessentialthattherebeanintegratedeffortindesign,material,process,tooling,qualityassurance,manufacturing,andevenprogrammemanagementforcompositestobecomecompetitivewithmetals.

Thecompositesindustryhasbeguntorecognizethatthecommercialapplicationsofcompositespromisetooffermuchlargerbusinessopportunitiesthantheaerospacesectorduetothesheersizeoftransportationindustry.Thustheshiftofcompositeapplicationsfromaircrafttoothercommercialuseshasbecomeprominentinrecentyears.

Increasinglyenabledbytheintroductionofnewerpolymerresinmatrixmaterialsandhighperformancereinforcementfibresofglass,carbonandaramid,thepenetrationoftheseadvancedmaterialshaswitnessedasteadyexpansioninusesandvolume.Theincreasedvolumehasresultedinanexpectedreductionincosts.

HighperformanceFRPcannowbefoundinsuchdiverseapplicationsascompositearmouringdesignedtoresistexplosiveimpacts,fuelcylindersfornaturalgasvehicles,windmillblades,industrialdriveshafts,supportbeamsofhighwaybridgesandevenpapermakingrollers.

Forcertainapplications,theuseofcompositesratherthanmetalshasinfactresultedinsavingsofbothcostandweight.Someexamplesarecascadesforengines,curvedfairingandfillets,replacementsforweldedmetallicparts,cylinders,tubes,ducts,bladecontainmentbandsetc.

Further,theneedofcompositeforlighterconstructionmaterialsandmoreseismicresistantstructureshasplacedhighemphasisontheuseofnewandadvancedmaterialsthatnotonlydecreasesdeadweightbutalsoabsorbstheshock&vibrationthroughtailoredmicrostructures.Compositesarenowextensivelybeingusedforrehabilitation/strengtheningofpre-existingstructuresthathavetoberetrofittedtomakethemseismicresistant,ortorepairdamagecausedbyseismicactivity.

Anexaminationofthediversityofsomeofthesenewerapplicationsandthesocio-commercialconsiderationsthatunderpintheirintroductiongivesaninstructiveinsightintothefutureofhighperformanceFRP.

Unlikeconventionalmaterials（e.g.,steel）,thepropertiesofthecompositematerialcanbedesignedconsideringthestructuralaspects.Thedesignofastructuralcomponentusingcompositesinvolvesbothmaterialandstructuraldesign.Compositeproperties（e.g.stiffness,thermalexpansionetc.）canbevariedcontinuouslyoverabroadrangeofvaluesunderthecontrolofthedesigner.Carefulselectionofreinforcementtypeenablesfinishedproductcharacteristicstobetailoredtoalmostanyspecificengineeringrequirement.

Whilsttheuseofcompositeswillbeaclearchoiceinmanyinstances,materialselectioninotherswilldependonfactorssuchasworkinglifetimerequirements,numberofitemstobeproduced（runlength）,complexityofproductshape,possiblesavingsinassemblycostsandontheexperience&skillsofthedesignerintappingtheoptimumpotentialofcomposites.Insomeinstances,bestresultsmaybeachievedthroughtheuseofcompositesinconjunctionwithtraditionalmaterials.

WhyComposites?

Compositesareabletomeetdiversedesignrequirementswithsignificantweightsavingsaswellashighstrength-to-weightratioascomparedtoconventionalmaterials.Someadvantagesofcompositematerialsoverconventionalonearementionedbelow:

∙Tensilestrengthofcompositesisfourtosixtimesgreaterthanthatofsteeloraluminium.

∙Improvedtorsionalstiffnessandimpactproperties

∙Higherfatigueendurancelimit（upto60%oftheultimatetensilestrength）.

∙30-45%lighterthanaluminiumstructuresdesignedtothesamefunctionalrequirements

∙Lowerembeddedenergycomparedtootherstructuralmaterialslikesteel,aluminiumetc.

∙Compositesarelessnoisywhileinoperationandprovidelowervibrationtransmissionthanmetals

∙Compositesaremoreversatilethanmetalsandcanbetailoredtomeetperformanceneedsandcomplexdesignrequirements

∙Longlifeoffersexcellentfatigue,impact,environmentalresistanceandreducedmaintenance

∙Compositesenjoyreducedlifecyclecostcomparedtometals

∙Compositesexhibitexcellentcorrosionresistanceandfireretardancy

∙Improvedappearancewithsmoothsurfacesandreadilyincorporableintegraldecorativemelamineareothercharacteristicsofcomposites

∙Compositepartscaneliminatejoints/fasteners,providingpartsimplificationandintegrateddesigncomparedtoconventionalmetallicparts

Composites:

TheFutureTrends

Armedwithawidegamutofadvantages,compositeshaveakeyroletoplayinthegrowingmarketinIndia.Compositeshavemadeanentryintodiverseend-usesegmentsandthedevelopmentaleffortsforfindingnewercompositesforexisting&novelapplicationsisanareaoftoppriority.

TransportationSector

Automobiles

Despitethepotentialbenefitsoflighterweightanddurabilityresultingfromcorrosionresistance,advancedcompositesarenotrecognizedasamaterialofchoiceintheneartermforautomotiveapplications.Significantchangesonabroadspectrumwouldberequiredtomakeadvancedcompositesattractiveforwidespreadcommercialuseincarsandtrucks.Theprincipalbarrieristhehighcostoftheraw&fabricatedmaterialswhencomparedtoexistingoptions.

Howeverthereareopportunitiesforadvancedcompositesinspecificcomponentsinthecommercialautomotivesector.Inspecialtyvehiclesofseveraltypes,producedinsmallnumbersadvancedcompositematerialshaveanopportunitytodemonstratetheirperformancebenefits,apartfromtherequirementsofthecompetitivemarketplace.

ThecompositeindustryworldwideisinvestinginprocessimprovementsforthemouldingofpolymercompositesusingformsofconventionalE-glassinmid-levelperformanceresins,boththermoplastic&thermoset.Automobilessegmentofcompositesaccountsforabout50%ofthethermoplasticand24%ofthethermosetcompositemarketintheworld.

Glass-reinforcedthermoplasticpolymerisapromisingmaterialforweightreductionbecauseoftherelativelylowcostofthefibre,itsfastcycletimeanditsabilitytofacilitatepartsintegration.Carbonfibrereinforcedpolymerisanothercandidatebutwillrequirebreakthroughsincostandmanufacturingtechniquestobecosteffectiveforhighvolumeproduction.

Pressureforreductionsinenergyuseandloweremissionslevelsmakesadvancedcompositesafavourableoptionfortheautomotivesector.Thecompositesusageinthissectorisestimatedaround3500TPAby2005AD.Thelikelyfuturebusinessopportunitiesinautomotivesectorarementionedbelow:

∙PultrudedDriveshafts

∙RTMPanel

∙FiberGlass/EpoxySpringsforHeavyTrucksandTrailers

∙RockerArmCovers,SuspensionArms,WheelsandEngineShrouds

∙Filament-WoundFuelTanks

∙ElectricalVehicleBodyComponentsandAssemblyUnits

∙ValveGuides

∙AutomotiveRacingBrakes&TrainBrakes

∙ClutchPlates

ThoughnotmuchprogresshasbeenmadeinIndiatowardsproductdevelopmentefforts,thisareameritsattentionandholdsalotofpromise.TheprospectsofexportofcompositescurrentlyarelowbecauseIndiadoesnotenjoyanycomparativeadvantageeitherinrawmaterialsorinprocessingcosts.

Theotherareawhichholdspromiseforthecomingdecadeistheuseofmetalmatrixcompositesforcertainautocomponents.Themainadvantageofsuchcompositematerialsystemsisthattheirphysical,mechanicalandthermalpropertiesaretailorableandcandrasticallysurpassthoseofreinforcedmetals.

MMCcanbeextruded,forged,investmentcast,rolled,machined,andheattreated.TransportationapplicationsrepresentoneofthelargestdemandsegmentsforMMCs,andincludeturbineandcombustionenginecomponents,discbrakesandbrakeparts,anddriveshaftcomponents.

Becauseoftheiruniqueproperties,metalmatrixcompositesarealsogaininginterestinahostofhighperformanceapplicationsacrossanumberofindustries.DemandforMMCsisgrowinginthetransportation,electronics,telecommunicationsandpollutioncontrolsectors.ItisexpectedthatMMCsmayexperienceadouble-digitincreaseacrosstheseindustrialmarketsthrough2003.

Marine

Withcompositesexhibitingexcellentresistancetothemarineenvironment,theirapplicationshavemadegoodinroadsinthemarinesectorworldwide.Complexconfigurations&theadvantagesofseamlesshullswerethemaindrivingfactorsinthedevelopmentofFRPboats.

Racingpower-boatsemployadvanced&hybridcompositesforahigherperformancecraftanddriversafety.Majorstructuralelementsviz.deckhouses,hatchcovers,kingsposts&bowmodulesappearstobeverywellsuitedforFRPconstruction.

InIndia,compositeapplicationsinmarinesegmenthasmadesomebeginninginthelastdecadeinhighspeedboats,navalvessel