胶粘剂对异种镁合金激光胶焊热作用过程的影响机制.pdf 6页

'中国科技论文在线http://www.paper.edu.cnThelaserthermaleffectontheadhesiveinlaserweld#bondingdissimilarMgalloysprocess*5WangHongyang,FengBaoqiang(DalianUnviersityofTechnology,SchoolofMaterialsScienceandEngineering)Abstract:TheeffectoflaserweldingontheadhesivewasdiscussedinthelaserweldbondingMgalloysprocess.ThedecomposedadhesivewasobservedbytheSEM,andthetensileshearloadofthelaserweldbondingMgjointsandtheadhesivejointsweremeasuedindifferentconditions.Theresults10showedthattheinvalidadhesiveareawasasincreaseasthelaserbeampower,whichinfluencethepropertyofthejointobviously.Thetensileshearloadwasreducedwiththedecreaseofadhesivethicknesswhentheadhesivethicknesswaslessthan0.15mm.Whentheinvalidareaadhesivewaslessthan1mm,theinfluenceoftheahesivedecompositionmadelittleharmfuleffectonthepropertyofthejoint15Keywords:weld;laserweldbonding;adhesive;interlayer;Mgalloys0IntroductionWiththequickdevelopmentofnewadhesive,adhesivebondingasatraditionallinkinthe[1]equipmentmanufacturingsectorwasusedmoreandmorewidely.Itwaspossibletoobtainthe[2-3]20highpropertyforthebondingofmetalsbyusingthestructuraladhesives.Adhesivebondinghadmanyadvantages,comparedwiththecommonweldingmethod,suchassimpleprocess,[4-5]favorablefatiguepropertiesandbondingthedissimilarmetals.Atthesametime,adhesivebondingwouldbeeasilybrokeninhighorlowtemperatures,whichlimitedtheusingofadhesive[6]bondinginmanykindsofstatement.25Inordertoincreasetheapplicationoftheadhesivebonding,manyresearchersdeveloped[7]specialadhesivetoimprovethebondingproperty.Notonlythat,weldbondingasacombinationofweldingandadhesivebondingwasusedtojoiningmanymetals.Weldingbondingwasusedwidelyintheautomotiveweldingprocess,whichmadethefatiguepropertyofthejointimproved[8]obviously.Anditwasreportedthatthelaserspotweldingandadhesivebondingcouldbeused[9-10]30tojointhelightmetalssuchasAlalloy,whichwasusedintheproductionofplanebyEWI.Afterthatlaserweldbondingasanewkindofweldingmethod,whichwasputforwardasan[11]alternativetolaserweldingandadhesivebonding,wasusedtojoinMgalloysandMgtoAlalloyssuccessfully.Intheprocessoflaserweldbondingmethod,theadhesiveinthefusionzonecouldbe35decomposedwiththethermaleffectoflaserwelding,whichwouldinfluencethemicrostructureofthejoint.However,excepttheadhesiveinthefusionzone,theadhesiveneartothefusionzoneisstillinfluencedbythelaserweldingeffect,whicheveninfluencesthepropertymoreobviously.Therefore,inthispapertheadhesiveconversionisstudiedcarefullyinthispaper,inordertounderstandthefailuremechanismoftheadhesiveinheateffectzone(HAZ).Furthermore,the40reliabilityevaluationmethodofthelaserweldbondingjointisdiscussed.Itcouldbehelpfulforthefurtherresearchonthehybridweldingmethodofweldingandadhesivebonding.1ExperimentsSamplesofextrudedAZ31Mgalloy(100×30×1.5mm)andAZ61Mgalloy(100×30×1.5mm)wereusedinexperiment.ThechemicalcompositionsofthesetwometalsareshowninTab.1.TheFoundations:DoctoralProgramoftheMinistryofEducation（No.20130041120004）Briefauthorintroduction:WangHongyang(1982),Male,AssociateProfessor,Dissimilarwelding.E-mail:wang-hy@dlut.edu.cn-1- 中国科技论文在线http://www.paper.edu.cn45experimentswerecarriedoutusingapulsedNd-YAGlaserwithamaximumaverageoutputpoweras800W.Thelaserpowerintheexperimentwas280Wto500W.Theweldingspeedwas-1300mm·min.Thedefocusingamountwas-3.5mm.TheconfigurationoftheLWBspecimensisshowninFig.1.TheadhesiveusedinexperimentwasepoxyadhesivemadebyHenkelCo.Oxidefilmonthespecimensurfacewasremovedby800gridsemerypaperbeforewelding,thendegreasedby50acetoneandtrichloroethylene.Tab.1ThecomponentofAZ31B、AZ61magnesiumplate（mass,%）MaterialsMgAlZnMnCaSiCuNiFeAZ31Brest3.111.120.42<0.040.10<0.05<0.005<0.005AZ61rest6.440.700.24<0.040.04<0.05<0.005<0.005Fig.1TheconfigurationoftheLWBspecimens552Resultsanddiscussion2.1ThemicrostructureofLWBMgalloysjointandtheadhesiveThedissimilarMgalloyswerejoinedbythelaserweldbondingtechnologysuccessfully,andthemicrostructureofthejointisshownintheFig.2.Itwasfoundthattherewasnoweldingdefectinthejoint.Thegrainsintheheateffectzone(HAZ)wasnotobviouslyenlarged.60(a)Themacrostructureofjoint(b)TheMicrostructureoftheHAZFig.2MicrostructuresofthelaserweldbondingMgalloyThemicrostructureoftheadhesiveattheedgeofthefusionzoneisshowninFig.3.Theadhesionareawouldbedividedintotwoparts,whichwerethecommonadhesivebondingareaandthe65decomposedarea.Incommonarea,theadhesivewasjoinedthedissimilaralloys.Thereweresomesmallholesintheadhesivelayer.Closetothetopplate,theadhesiveshowedaclusterstructure.Itmeantthatpartoftheadhesivewasdecomposedinthelaserweldingprocess.IntheexperimenttheEDSwasusedtoanalysisthedecompositionofthisarea,butwhentheelectronbeamscanthesurfaceoftheresidualofadhesive,itwasdecomposedslowly.Thereforeitcouldbedeterminedthatthispart70oftheadhesivewasmainlycomposedofthepolymericcompounds.Thispartofinvalidadhesive-2- 中国科技论文在线http://www.paper.edu.cnwouldmakeharmfuleffectonthepropertyofthewholelaserweldbondingjoint.Theareaoftheinvalidadhesivewaschangedwiththeweldingparameters.(b)Commonadhesiveinterlayer(b)Decomposedadhesive75Fig.3MicrostructuresoftheadhesiveatdifferentpartsInlaserweldbondingprocess,theadhesivewouldbedecomposedwiththethermaleffectoflaserbeampower.Theadhesiveinthelaserweldingfusionzonewouldbedecomposedintoseveralkindsofgases.Forexample,themaincontentoftheadhesiveusedinthisexperimentisbisphenol-Aepoxy.Itwouldbedecomposedasshowninformula1:80(C11H12O3)n→CxHy+nCO+nCO2Theadhesiveinthefusionzonewouldbedecomposedandescapefromtheweldingpool,whichwouldinfluencethemeltingprocessinthefusionzone.Howevertheadhesiveneartothelaserweldingjointwasstillinfluencedbythelaserweldingthermaleffect.Althoughthetemperatureattheedgeofthefusionzonewasobviouslylowerthanthatoflaserweldingpool,itwasstilloverthevalid85temperatureoftheadhesive.Thereforepartiallyoftheadhesivewasdecomposedwiththethermaleffectofthelaserwelding.2.2TheinfluenceofthelaserpowerontheareaoftheinvalidadhesiveInordertounderstandtheinfluenceofthelaserbeampowerontheareaofdecomposedadhesive,theinvalidareaoftheadhesivewasmeasured.Fig.4presentstheareaoftheinvalidadhesivevaried90logicwiththeincreasingoflaserbeampowers.Thefullypenetrationweldingjointwasobtainedasthelaserpowerwasabout450W.Therefore,whenthelaserbeampowerwasover450W,theinvalidadhesiveareawasnotmeasured.Itwasshownthattheareaoftheinvalidadhesivewasasincreasingasthelaserbeampower.Theincreasingtendencyoftheinvalidadhesiveareareducedgradually.TheareaofinvalidadhesivewasinfluencedbytheweldpoolwidthinbottomMgalloy,whichwasdecidedby95thelaserweldingtemperaturedistributionintheweldingpool.Thetemperaturearoundtheweldingpoolcouldbemeasuredbythethermalcouples,asshownintheFig.5.Fig.4InvalidareaofadhesiveindifferentlaserbeampowerThetemperaturedistributionsinthebottomMgalloynearbythefusionzoneareshowninFig.6.100Anditwasfoundthatwhenthetemperaturewasover450K,theadhesivebondingpropertywouldbeinfluenced.Itmeansthatexcepttheadhesivefullydecomposition,theadhesivebondingjointwas-3- 中国科技论文在线http://www.paper.edu.cninfluencebythelaserweldingpower.Butthiskindofadhesivemakesrelativesmalleffectonpropertyofthejoint.ThereferencetemperaturesoftheinvalidadhesiveareshownintheFig.6too.Itcouldbefoundthatthelaserbeampowerhadlittleeffectontheadhesiveinvalidtemperature.However,the105invalidareaoftheadhesivewasdecidedbythetemperatureapproachtotheAlfusionzone,whichwasasincreasingasthelaserbeampower.Fig.5ThesetupoftemperaturemeasurementapproachtoAlfusionzone110Fig.6Temperaturedistributionsinthebottomplate2.3Discussionofinvalidadhesiveontheweldingstructure.Ingenerally,theadhesivebondingloadwasmainlydecidedbythebondingarea.Inordertofurtherunderstandtheinvalidadhesiveareaonthetensileloadoftheadhesivebonding,theshearload115ofadhesivewasmeasuredwithdifferentconstructions.TheadhesivebondingstructuresareshownintheFig.7.Inthisfigure,areaAisthepartwithoutadhesive,whichchangesfrom0to6mm.Fig.7TheconfigurationofadhesivebondingjointTheresultsoftheadhesivebondingjointwithdifferentadhesivebondingareaareshowninthe120Fig.8.ItcouldbefoundthatthetensileshearloadofthejointwasreducedgraduallywithadditionoftheareaA.WhentheuncoatedareaAwaslessthan2mm,thedecreaseoftheadhesivebondingtensileshearloadwaslimited.-4- 中国科技论文在线http://www.paper.edu.cnFig.8Theadhesivebondingpropertywiththeadditionofuncoatedareaa125ThethicknessofadhesivewouldmakeeffectonthepropertyofthejointasshownintheTab.2.TheadhesivebondingspecimenwaspreparedasshownintheFig.7withouttheuncoatedarea.TheresultsshownintheTab.2wastheaveragevalueofthreespecimens.Itcouldbefoundthatthethicknessoftheadhesivewouldmakeobviouslyeffectonthepropertyofthejoint,whenthethicknessoftheadhesivewaslessthan0.15mm.However,itwashardtocontrolthedecompositionofthe130adhesivebycontrollinglaserweldparameters,whenthethicknessoftheadhesivewasover0.1mm.Therefore,thethicknessoftheadhesivewascontrolledbetweenthe0.1mmandthe0.15mm.Tab.2TensileshearloadsofadhesivebondingjointsPreparedadhesiveMeasuredTensileshearthicknessthicknessload0.050.485.5KN0.10.097.9KN0.150.158.4KN0.200.198.1KN3Conclusion135Inthispaper,itwasfoundthattheadhesivewouldbedecomposedinlaserweldbondingMgalloys.Theareaofadhesivedecompositionwouldbeincreasedwiththeincreasingoflaserbeampower.Astheinvalidareaoftheadhesivewaslessthan2mm,theinfluenceoftheadhesivedecompositionwouldmakelittleeffectontheLWBjointproperty.Whentheadhesivethicknesswaslessthanthe0.2mm,thelaserweldbondingjointpropertywouldbeimproved,withtheincreasingoftheadhesive140thickness.References[1]AHiggins,Adhesivebondingofaircraftstructures[J],InternationalJournalofAdhesionandAdhesives,2000,20(5):367-376.145[2]O.Lunder,B.Olsen,K.Nisancioglu,Pre-treatmentofAA6060aluminiumalloyforadhesivebonding[J],InternationalJournalofAdhesionandAdhesives,2002,22(3):143-150.[3]P.Molitor,V.Barron1,T.Young,Surfacetreatmentoftitaniumforadhesivebondingtopolymercomposites:areview[J],InternationalJournalofAdhesionandAdhesives,2001,21(2):129-136.[4]Zhong-xiaLiu,Rui-naSun,Zhi-pingMao,Pei-chungWang,Effectsofphosphatepretreatmentandhot-humid150environmentalexposureonstaticstrengthofadhesive-bondedmagnesiumAZ31sheets[J],SurfaceandCoatingsTechnology,2012,206(16):3517-3525.[5]Jin-HweKweon,,Jae-WooJung,Tae-HwanKim,Jin-HoChoi,Dong-HyunKim,Failureofcarboncomposite-to-aluminumjointswithcombinedmechanicalfasteningandadhesivebonding[J],CompositeStructures,2006,75(1):192-198.155[6]S.Bhowmik,H.W.Bonin,V.T.Bui,R.D.Weir,Durabilityofadhesivebondingoftitaniuminradiationand-5- 中国科技论文在线http://www.paper.edu.cnaerospaceenvironments[J],InternationalJournalofAdhesionandAdhesives,2006,26(6):400-405.[7]G.Meschut,O.Hahn,V.Janzen,T.Olfermann,Innovativejoiningtechnologiesformulti-materialstructures[J],WeldWorld,2014,58:65-75.[8]ZhanxiangLing,YangLi,ZhenLuo,YueqiaoFeng&ZhengminWang,ResistanceElementWeldingof6061160AluminumAlloytoUncoated22MnMoBBoronSteel[J],MaterialsandManufacturingProcesses,2016,31(16),2174-2180.[9]GrantWilson,LaserWeld-BondingMethodDevelopedforAluminium[J],AdvancedMaterials&Processes,2005,163:31.[10]RobertW.MesslerJr,ScotBohnenstiehl,JohnLevene,ErikaJohnsonandLuoChen,Apressure-assisted165approachforlaser-beamweld-bondingAlalloystructureforautomobiles[J],AssemblyAutomation.2004,24(4):370-378.[11]LimingLiuandHongyangWang,MicrostructureandPropertiesAnalysisofLaserWeldingandLaserWeldBondingMgtoAlJoints[J],MetallurgicalandMaterialstransactionsA,2011,42(4):1044-1105170胶粘剂对异种镁合金激光胶焊热作用过程的影响机制王红阳，冯宝强（大连理工大学，材料科学与工程学院）175摘要：本文重点讨论了镁合金激光胶焊过程中，激光作用对胶粘剂的影响机制。采用扫描电镜分析了胶粘剂失效区域结构，测试了不同条件下激光胶焊及胶接试件的拉伸载荷。测试结果表明，随着激光能量的增大，胶粘剂失效区域逐渐增大，胶粘剂的失效会对激光胶焊接头性能产生直接影响。研究发现，当胶层厚度小于0.15mm时，胶接试件的性能随着胶粘剂厚度的增加而增加，当胶粘剂的失效区域小于1mm时，对整个激光胶焊及胶接接头性能的影180响并不明显。关键词：焊接；激光胶焊；胶粘剂；中间层；镁合金中图分类号：TG49-6-'