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2.Makesuretheimageisbehindallobjectsonthepage.Text/colorbars/colorboxes/logos3.DELETETHESEINSTRUCTIONBOXWHENDONE2.Makesuretheimageisbehindallobjectsonthepage.Text/colorbars/colorboxes/logos3.DELETETHESEINSTRUCTIONBOXWHENDONE•October2012FinancialsAutomotiveVS•NovelisAutomiveEuropeMichaelHöhnkeTechnicalSeminarC.JoiningSGM-NovelisC.JoiningC.1jointgeneralQuestionsWhenOEMsjointhedifferentsystem,aretherespecificcautionforjoining?•Steel–aluminiumcontact:=corrosion!-insulationbetweenblanks-coatedrivets•LinejoiningincreasestiffnesscomparedtopointjoiningWhatkindsofmethodsareusedforcorrosionprotectionbetweendifferentmaterial?•Adhesive•WaxCopyright2007NovelisSwitzerlandSACorrosionProtectionConceptContent•Mechanicaljoining–Hemming–Blindriveting–Selfpiercingriveting(SPR)–Clinching•Adhesivebonding•Welding–Resistancespotwelding–FrictionstirweldingMechanicaljoining•Automotiveindustryusehemmingfixturesforlotsofhang-onpanels(Doors,hoods,decklids,…).Itisyetthemostexpensiveofthejoiningmethod.•Standardhemmingjoiningtechnologyuseexpensivemachinery(hemmingpress,beadingtool)whicharenotflexible.HemmingCostpermeter[€]MIG0.08RSP0.05Hemming0.21Adhesivebonding0.12SPR0.15Clinching0.04Laserwelding0.51*withouttooldepreciationCostsforequi-resistantjoints/m*Hemming,borderingandfoldingmethodsarefundamentaljoiningtechniquesforthemanufacturingofautomotivestructures.Thequalityofthehemwithregardstominimumbendradiusdependson:•alloy,•heattreatment•forminghistoryofthesheet/part,•thickness•formingprocessparametersStep1:bending90°Step2:hemming45°Step3:folding180°HemmingThefiguresatrightshowtwopossibledesignsofhemming:•type1(FlatHem):standardgeometry•type2(RopeHem):ifductilityofmaterialiscritical.HemmingGoal:reducevisiblegapbetweentwoclosures.BadNauheim,7/8November2002,TheAluminiumAuto.ProcessChainHemmingExampleforcriticalhemmingrequirementsinnerradius:0.43mmlocalgauge:1.08mmprestrain:10%bendingfactor:0.3600.20.40.60.811.205101520Prestrain(%)Bendingfactor(f=ri/t)Ac-121Ac-170windowareaa-pilar-hingeareaUseahemmingfriendlyalloyforouterpanelinnerradius:0.56mmlocalgauge:1.04mmprestrain:13%bendingfactor:0.40SafeareawithAlloyBSafeareawithAlloyACriticalareawithAlloyACriticalareawithAlloyBAlloyAAlloyBHemmingexamples:AudiA6HoodSide-HemmingHemmingexamples:AudiA8RearDoorHemmingexamples:DetailsA8RearDoorHemmingrollerfixedonrobothead=movesaroundthecomponentandturnsovertheflangewithinseveralpasses(usually3to4).•HemmingVelocity*:app.200mm/s•HemmingForce*:app.300to2000N•FlangeAngle:0°to180°•HemmingAngleapp.30to80°percirculationRollerHemming-GeneralPrinciplePre-hemmingInnerpanelOuterpanelHemmingnestvFinalHemmingFInnerpanelOuterpanelHemmingnest*dependsonpanelthickness,componentcontourandhemmingrolldiameter•Advantages–Sizeoftheequipment/Floorspace–Flexibility–Easeoftuning(Robotsprogramming)–Reductionofinstallationinvestment–Improvementofprocessstability(incomparisonwithstdhemming)–Noinfluenceonthesurfacequality•Disadvantages–Slowcycletime(dependingonthenumberofrobotused)RollerHemming:Advantages/Drawbacks•Rollerhemmingtechnologyhasbeenusedforthecut-outsoftheOpelMeriva’ssunroofs.•Opel’schoiceshavebeenmotivatedbyrollerhemminglowcostandflexibility.RollerHemming:OpelMerivaSource:H.Henkel,IndustryFirst:RollerHemmingforSunroofs,AutoTechnology5/20034stepshemming:•ReardoorofJaguarXJLWBarerollerhemmedRollerHemming:JaguarXJLongwheelbaseversionSkinpanel:AA61110.93mmInnerpanel:NG57541.20mmHemmingdesign:FlathemCycletime(completecell):240sRivettechnologiescanbesubdividedintotwogroups:1.Standardrivetsystems(blindrivets):•requiringpre-punchedholes:•canbeappliedfromonesideonly=ofgreaterimportanceinautomotiveapplications.2.SelfPiercingRivetssystems•requiringnopre-punchedholes•particularlyusefuljoiningtechniqueforrepairworkonaluminiumautomotivestructures,oftencombinedwithadhesivebondingRiveting:IntroductionCharacteristicfeaturesofblindrivetingsystems:·doublesidedaccessnotnecessary,·pre-punchingordrillingnecessary,·highloadbearingcapabilityofscrewthreadsinthinpanels,Theblindrivetconsistsoftherivetsleeveequippedwithatoolpin.Whiletheshaftofthetoolpinisdiscardedaftersetting,thepinheadremainspermanentlyattached.BlindRiveting:Principle•Punchononeside/shapeddieontheunderside•Onestepoperation,nopre-drillingofholesnecessary•Withsolidrivets,thepunchdrivestherivetwhichpiercesthesheetpliescompletely.•TheselfpiercingrivetsaregenerallymadeofsteelcoatedwithAlZnpowdertopreventgalvaniccorrosion(aluminiumselfpiercingrivetscanbeusedinspecialcases)•Therivetisgenerallyappliedfromthedirectionofthethinsheetintothethicksheet,orfromthelowstrengthmaterialintothehighstrengthmaterial.•Rivetsshouldbespacedtoavoidcontactwithneighbouringrivetsorthestrainedareaimmediatelyaroundthem.SelfPiercingRiveting(SPR):PrincipleandrulesBenefits:–Simple,one-stepprocesswithnopre-drilledholesrequired;–Fast,automatedoperationpossible;–Suitableformanydifferentmaterialsandmaterialscombinations;–Littleornodamagetopre-coatedmaterials;–Joiningofmorethantwosheetspossible;–Nofumeorheatandlownoiseemission;–Longtoollife(typicallygreaterthan20,0