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_______________________________________________________________________________________________________________________________20041020B20000074TG306_________________________20041020ResearchonContinuousCastingProcessforLayeredCu/AlBimetallicCompositeRods100083DoctorDegreeCandidateSunDeqinSupervisorWuChunjingSchoolofMaterialsScienceandEngineeringUniversityofScienceandTechnologyBeijing30XueyuanRoadHaidianDistrictBeijing100083P.R.CHINAI___________20041020_________20041020ICuZn-AlDelphiAlCuAlCuCuAlCuAlAl/CuCuAlAl-CuAlCuAlCuAl8L18(38)II660.37Al-Cu548IIIResearchonContinuousCastingProcessforLayeredCu/AlBimetallicCompositeRodsInthisstudy,broughtforwardtwokindsofnoveltechnologiesforlayeredbimetalliccompositerods:Dual-MouldcontinuouscastingandCore-Fillingcontinuouscasting,andstudiedtheirprocesslawsbytwomeansoftechnologiesexperimentandnumericalsimulation.Thetechnicalprincipleofdual-mouldscontinuouscastingisthat,(1)adoptinganewequipmentstructureofanupper-mouldandalower-mould,whichinstalledinaverticaldirection;(20theinnermetalwaspouredintoupper-mouldandformedfrozenrod;(3)theinnermetallicrodwasdraggedintothelower-mould,andsynchronouslytheouter-layermetallicliquidwaspouredintolower-mould;(4)thebondinglayerwasformedbytheinter-reactionbetweenthetwometals.Basedonitstechnicalprinciple,exploitedasetofcontinuouscastingequipments,andmadeexperimentsforbimetallicrods,whichCuusedasinner-materialandZn-Alalloyascoatingmaterial.Inordertooptimizethisprocess,compilednumericalsimulationprogramusingDelphisoftware;obtainedtemperaturefieldsanddensityfieldsofvariousprocessconditionsbyorthogonaltest;thesimulatingresultwasadjacenttotechnicalexperimentresult.Analyzedthecharacteristicsoftempoeraturefieldanddensityfield,andstudiedtechniqueruleanddiscussedthjecompoundingmechanism.PointedthatthecompoundingmechanismofDual-mouldscontinuouscastingprocesswerefittedtomanufacturingmetalliccompositematerialsoflow-meltingpointmetalcoatingonhigh-meltinglpointmetalmatrix.TestednumericalsimulationbyAlasinnermaterialsandCuascoatingmaterials,andprovedthatthiskindoftechniquewasn’tabletobemadeuseofmanufacturingmetalliccompositerodsofhigh-meltingpointmetalcoatingonlower-meltingpointmetalmatrix.Studiedanoveltechniqueofdirect-formingcontinuouscastingprocesscalledCore-Fillingcontinuouscasing,whichsuitedftomanufacturingakindofcompositematerialsofmelting-pointofcoatingmetalhigherthaninner-metal,suchasCucoatingmaterials,designedthetechnicalprojectandexperimentalequipoments;performedthefeasibilityexperimentofCucladAlcompositebillets.Theexperimentresultmadeknownthat,forthisprocess,theinter-reactionbetweenCuandAlmainlybehavedtheCuelementdiffusiontoAlmeltingliquid.Theinter-reactionbetweenCuandAlmainlybehavedtheCuelementdiffusiontoAlmeltingliquid.Theinter-reactionbetweenCuandAliscomplexandunmanageable,brittlecompoundeasilyproduced;theprocesswasunmanageable,easilybroughtsomeillphenomenon,oneisthatCurodwasinvadedoverly,evenCurodwaspenetratedandAlmeltingliquidwaspouredout;thesecondwasthattheinter-reactionbetweenCuandAlwasn’tperformed,andthebonding-layerwasn’tformed.Formingfinebondingresultneedhighrequirementtotechnicalfactors,sostudieditstechnicallawbynumericalsimulation.Basedontheexistedexperimentequipment,compilednumericalsimulationIVprogramusingDelphisoftware;Alasinner-materialandCuascoatingmaterial,usingheattransferequitationinformofcolumnedcoordinateandselected8maintechnicalparameterssuchaspouringtemperatureandvelocityofdraggingbilletandothers,anddesignedL18(38)orthogonaltable;obtainedtemperaturefieldsofvariousprocessconditionsbyorthogonaltest.Analyzedthecharacteristicsoftemperaturefields,andstudiedtechniqueruleanddiscussedthecompoundingmechanism.PointedoutthatthecompoundingmechanismofCore-fillingcontinuouscastingforCucladAlbimetallicmaterialsgavepriortoelementdiffusion;ifwinthegoodbondinglayer,theaveragetemperatureofAlmeltingliquidandCucubebilletiinner-layertemperatureatthepositionofpouringtubebottomwillberestrictedintherangebetweenAlmeltingpoint660.37andAl-Cueutectictemperature548,andAl-Cucompositerodshouldbecooledinarapidvelocity.Keywords:bimetallics;continuouscasting;Dual-mouldstechnology;Core-Fillingprocess;numericalsimulation;diffusionmechanism11......................................................................................................................................1........................................................................................................................1.............................................................................................................3...................................4........................................................4.....................................................................4.................................................................5.............................6..........................................................................7..........................................................................8..............................................................