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《Three-dimensional heat and material flow during friction stir welding》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、ActaMaterialia55(2007)883–895www.actamat-journals.comThree-dimensionalheatandmaterial?owduringfrictionstirweldingofmildsteela,*abaR.Nandan,G.G.Roy,T.J.Lienert,T.DebroyaDepartmentofMaterialsScienceandEngineering,ThePennsylvaniaStateUniversity,UniversityPark,PA16802,USAbMaterialsSci
2、enceandTechnology,LosAlamosNationalLaboratory,LosAlamos,NM,USAReceived15April2006;receivedinrevisedform3September2006;accepted7September2006Availableonline4December2006AbstractThree-dimensionalviscoplastic?owandheattransferduringfrictionstirweldingofmildsteelwereinvestigatedbothex
3、perimentallyandtheoretically.Theequationsofconservationofmass,momentumandenergyweresolvedinthreedimensionsusingspatiallyvariablethermo-physicalpropertiesandamethodologyadaptedfromwell-establishedpreviousworkinfusionwelding.Non-Newtonianviscosityforthemetal?owwascalculatedconsideri
4、ngtemperatureandstrainratedependent?owstress.Thecomputedresultsshowedsigni?cantviscoplastic?ownearthetoolsurface,andconvectionwasfoundtobetheprimarymechanismofheattransferinthisregion.Also,theresultsdemonstratedthestrongthree-dimensionalnatureofthetransportofheatandmass,rea?rmingt
5、heneedforthree-dimensionalcalculations.Thestreamlinesofplastic?owindicatedthatmaterialwastransportedmainlyalongtheretreatingside.Thecomputedtem-peratureswereingoodagreementwiththecorrespondingexperimentallydeterminedvalues.ó2006PublishedbyElsevierLtdonbehalfofActaMaterialiaInc.Key
6、words:Frictionstirwelding;Numericalmodeling;Mildsteel;Plastic?ow;Heattransfer1.Introductionsimultaneouslyoccurringphysicalprocessesa?ecttheheat-ingandcoolingratesandthestructureandpropertiesofFrictionstirwelding(FSW)isasolid-stateweldingpro-theweldedjoints.cess.Thetoolusuallyhasal
7、arge-diametershoulderandaTheFSWprocesswasdiscoveredin1991atTWI[1].smallerthreadedpin.TheplatestobeweldedarealignedSincethenFSWhasbeenwidelystudiedbothexperimen-togetherandclampedusing?xtures.Acylindricalholeistallyandtheoreticallytobetterunderstandboththeweld-drilledatoneendofthew
8、orkpieceonthecenterlineandingproc
