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简介：Withthickplatesof2219high-strengthalloy,themicrostructuresofweldedjointswithtwinwireMIGweldingwereanalyzed.Experimentalresultsshowthatnohotcrackwasfoundintheweldduetodiscontinuousdistributionofcocrystallizationwithlowmeltingtemperature,butporosityisseriousinthefirstweldseamthatismainlycomposedofequiaxialgrainswithunevensizes.Asthepoorpositionofthewholeweldedjoint,fusionzonehasbigandcoarsegrains,unevenmicrostructures;Inquenchingzone,thereexistalotofsoakedmicrostructuresthatcocrystallizationwithlowmeltingtemperaturesoluteintomatrix,thusstrengtheningthemetalinthiszone;Inexcessiveagingzone,muchmorephasesthatdistributeevenlywillbeseparatedfromthematrix;Outsidethiszone,propertiesandmicrostructuresofthemetalarebasicallysimilartomatrixduetotherelativelylowtemperatureorunaffectedheatinthezoneduringwelding.

简介：TheprocesspropertiesandinterfacebehaviorofCO2laserbrazingwithautomaticwirefeedforgalvanizedsteelsheetswereinvestigated,inwhichthebrazingfillermetalwasCuSi3andnofluxwasused.Astotheappearancequalityofthebrazingseams,therolesoftheprocessingparameters,suchasbrazingspeed,wirefeedingrate,inclinationandfeedingdirectionofthewire,laserpower,spotdiameterandheatingposition,wereassessed.ThefurtherinvestigationindicatesthatthebehavioroftheactiveelementsSi,MnandZnaresignificantlyinfluencedbyenergyinput.Attheinterface,themicrostructureofthebasemetalwascomposedofcolumnarcrystalsandtheacicalarαsolidsolutionwasfoundonthefillermetalside.

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简介：WiththebackgroundofthecontrolofadditionalmechanicalforcedroplettransferinMIG/MAGwelding,regardingtheACservomotorascore,anoveloscillatingwirefeedingsystemhasbeendevelopedwithexcellentperformancesofcontrolanddynamicaccelerationwhichistested.Systemconstitutionandoperationprincipleareintroducedinthispaper.Influencesofparametersondynamicaccelerationperformanceareanalyzedanddiscussedemphatically,suchasoscillatingfrequency,oscillatingamplitudeanddraw-backspeed.Experimentalresultindicatesthataccordingtothetechniqueofweldingcontrol,thenovelwirefeedingsystemrespondsrapidlytovariouskindsofcontrolordersofwirefeedinganddraw-back,andrealizesflexiblecontrolofweldingwireaxialmovement,includingdynamicshifting,oscillatingandsoon.

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简介：Apilotwiredrawingmachineaswellaswireend-pointingrollerwasdeveloped.Usingthesemachines,awiredrawingtestforfourdifferentcoatingmaterialsandtwodifferentlubricantswasperformedasthereductionratioincreasedfrom10%to30%.Materialsusedforasubstrateinthisstudyareplaincarbonsteel(AISI1045)andultralowcarbonbainitesteel.Tocomputethefrictioncoefficientbetweenthecoatinglayerofwireandthesurfaceofdieforaspecificlubricant,aseriesoffiniteelementanalyseswerecarriedout.SEMobservationswerealsoconductedtoinvestigatethesurfacedefectsofwiredeformed.Resultsshowthatthebehaviorofdrawingforcevarieswiththelubricant-typeattheinitialstageofdrawing.Thepowder-typedlubricantwithalargeparticlecausestheretardationoffulllubricationontheentirecontactsurfaceandthelocaldelaminationofcoatinglayeronthewiresurface.Astheflowstressofasubstrateincreases,thedelaminationbecomessevere.

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简介：Inthethree-wireweldingsystem,aweldingprocessconsistsoftheoperationsoffourdevices,namelythreeweldingmachinesandonebogie.Theoperationsneedtobesynchronizedbyanumericalcoordinatecontroller(NCC).Inthispaper,wewilldiscussatask-job-procedurecubicprogramstructure.Underthisstructure,thedevicesaresynchronizedandisolatedatthesametime.Thiscubicprogramstructurecanalsobeusedasareferenceforothermulti-deviceormulti-unitmanufacturingprocesses.

简介：IntheautomaticCO2arcwelding,thealterationoftheverticaldistancebetweentheweldingtorchandtheworkpiecehasastrongeffectontheweldingparameterssuchasweldingcurrentandvoltage,withtheresultthattheappearanceandqualityofweldarenotsteady.Toweakentheinfluenceofthedistancealteration,amethodisputforwardinthepaper.Themethodisthatthealternatewire-feedcontrolisusedforcompensatingtheweldingcurrent.Onthebasisoftheoreticalanalysis,astaticnumericalmodelforalternatewire-feedcontrolisestablished.Theexperimentsshowthatthemodel-basedregulationofthewirefeedratecancompensatetheweldingcurrentandensuretheappearanceofweld.Whenthealterationofverticaldistancebetweenthetorchandtheworkpieceisgreater,notonlyisthewirefeedrateregulated,buttheoutputvoltageofthepowersourceisadjustedtoensuretheappearanceandqualityofweld.

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简介：Atypeofnovelinverterpowersupplysystemforhigh-powertwin-wirepulsedgasmetalarcwelding(GMAW)ispresentedmainlyfordealingwiththedisadvantagesoftheconventionalpowersupplyfortwin-wirepulsedGMAWofwhichtheoutputpowerisgenerallydifficulttoincreaseduetolimitationsofthepowerofsemiconductorsandthepowerdensityofmagneticdevices.Inthepowersuppliesforthemasterandslavearcs,thedigitalsignalprocessor(DSP)TMS320F28335isusedtoformtheDSP-basedsynergiccontrolsystemforparallelhigh-powerpulsedGMAW,whichachieveshigh-poweroutputoftwoparallelinverterscontrolledbyasingleDSP;master-slavecommunicationisachievedbyusingecontrollerareanetwork(eCAN)moduleofDSP,thusrealizinganti-phasepulseoutputofhigh-powertwin-wirepulsedGMAWandreducingtheinterferencebetweentwinarcs.Theexperimentresultsdemonstratethatthedesignedinverterpowersupplysystemforhigh-powertwin-wirepulsedGMAWcanbringabouthigh-powerefficiencyofwelding,stableweldingprocessandproperformationofwelds.

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简介：Thehotdeformationbehaviourof7075aluminiumalloyreinforcedwith10%ofSiCparticleswasstudiedbyemployingboth'processingmaps'andmicrostructuralobservations.Thecompositewascharacterizedbyemployingopticalmicroscopetoevaluatethemicrostructuraltransformationsandinstabilityphenomena.Thematerialinvestigatedwasdeformedbycompressioninthetemperatureandstrainraterangesof300-500℃and0.001-1.0s-1,respectively.Thedeformationefficiencywascalculatedbystrainratesensitivity(m)valuesobtainedbyhotcompressiontests.Thepowerdissipationefficiencyandinstabilityparameterswereevaluatedandprocessingmapswereconstructedforstrainof0.5.Theoptimumdomainsandinstabilityzonewereobtainedforthecomposites.Theoptimumprocessingconditionsareobtainedinthestrainraterangeof0.1-0.9s-1andtemperaturerangeof390-440℃withtheefficiencyof30%.