简介：Duetotheindividualelectricalandmechanicalcharacteristicsofresistanceweldingmachines,choiceoftherightmachineandweldingparametersforanoptimizedproductionisoftendifficult.Thisisespeciallythecaseinprojectionweldingofcomplexjoints.Inthispaper,anewapproachofcharacterizingtheelectricalpropertiesofACresistanceweldingmachinesispresented,involvingtestingandmathematicalmodellingoftheweldcurrent,thefiringangleandtheconductionangleofsiliconcontrolledrectifierswiththeaidofaseriesofproofresistances.Themodelpredictstheweldcurrentandtheconductionangle(orheatsetting)ateachsetcurrent,whentheworkpieceresistanceisgiven.

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简介：Amodelwasdevelopedtosimulatethetemperaturedistributionandnuggetformationduringresistancespotwelding(RSW)ofzinc-coatedsteels.Itemploysacoupledthermal-electrical-mechanicalanalysissimulatingthedynamicRSWprocess.Temperature-dependentthermal-electrical-mechanicalmaterialpropertieswereconsideredincludingcontact-resistance.Thecontactareawasdeterminedfromacoupledthermal-mechanicalanalysis.Alayeroftransitionelementswasusedtorepresentthechangeofcontactareabykillingoractivatingelements.Theheatgenerationandtemperaturefieldwerecomputedinacoupledthermal-electricalmodel.Alltheseanalysesweresolvedusingthecommercialfiniteelementmethod(FEM)basedonANSYScode,andsomeadvancedfunctionswereusedbywritingaparagraphofcodesbytheauthors.Comparedwiththeresultsfromonlycoupledthermal-electricalmodelinwhichcontactareawasuniformduringthewholeprocess,theresultmatchesbettertotheexperimentalresults.

简介：The304stainlesssteelstripsweredepositedonelayeroncarbonsteelbasemetalbyelectroslagstripcladding(ESC)andsubmergedarccladding(SAC),respectively.ThesolidificationmicrostructureofESCmetalwasanalyzedbytheopticalmicroscopy,scanningelectronmicroscopeandenergydispersivespectroscopy.Thecorrosionresistancestudiesofstripcladdingmetalswerecarriedoutin10%oxalicacidelectrolyticetchingtest.TheresultsshowedthatthecladdingmetalobtainedbyESCpresentedlowcontentofC,highcontentofCrandenoughalloyingelementofNiinthechemicalcomposition.ThetransitionzoneofESCwithsmallwidthwasalmostparallelwiththebasemetal,leadingtoalowerdilution.Therearethreetypesofsolidificationmodes(A→AF→FA)occurredintheESCmetalduetothedecreaseofcoolingrateanddegreeofdilutionfromthetransitionzonetothetopofESCmetal.Asaresult,themicrostructureofESCmetalexhibitedmainlyaustenitewithasmallamountofferrite,contributingtoachievementofbettercorrosionresistance.

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简介：Amethodwasdevelopedtorealizequalityevaluationoneveryweld-spotinresistancespotweldingbasedoninformationprocessingofartificialintelligent.Firstly,thesignalsofweldingcurrentandweldingvoltage,asinformationsource,weresynchronouslycollected.Inputpoweranddynamicresistancewereselectedasmonitoringwaveforms.Eightcharacteristicparametersrelatingtoweldqualitywereextractedfromthemonitoringwaveforms.Secondly,tensile-shearstrengthofthespot-weldedjointwasemployedasevaluatingtargetofweldquality.Throughcorrelationanalysisbetweeneverytwoparametersofcharacteristicvector,fivecharacteristicparameterswerereasonablyselectedtofoundamappingmodelofweldqualityestimation.Atlast,themodelwasrealizedbymeansofthealgorithmsofRadialBasicFunctionneuralnetworkandsamplematrixes.Theresultsshowedvalidationsbyasatisfactioninevaluatingweldqualityofmildsteeljointon-lineinspotweldingprocess.

简介：Anewtypeofhybridweldingmethodcalledresistanceplugwelding(RPW)wasfirstlyadoptedtoachievetheconnectingofdissimilarsteel,mainlyasforthepoorweldingcharacteristicsofhighstrengthsteelproducedbyincreasingcarbon,manganese,silicon,etc.MicrostructuresandmechanicalpropertiesofRPWjointwereanalyzedbyopticalmicroscope,micro-hardnesstestandsheartensilemeasurement.ExperimentalresultsindicatethattheRPWjointhasaroundedrectanglenugget,andthesizeislargerthanellipticalnuggetofresistancespotwelding(RSW)joint;thehardnessvalueofRPWjointisevenlydistributed,accordinglythereisnohardbrittlephases;thesheartensilestrengthofRPWjointincreasesby20%incomparisonwithRSWjointunderthesameweldingconditions.

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简介：ThisinvestigationwasperformedtostudyacousticfieldsignalinordertoimproveRSWquality.Researchersfirstlybuiltanacousticarraysensorsystem,whichincluded8MPA-416acousticsensors,dataacquisitioncardandLabVIEW.Thesystemobtainedtheacousticfieldinformationintheprocessofnuggetgrowing.Duetothenonlinearityfieldsignal,arraysensoralgorithmwasutilizedtoquantitativelyanalyzethecharacteristicsofacousticfieldandreducednoise.TheexperimentandcalculationresultsshowthatarraysensorsystemcanacquireacousticfieldsignalofnuggetgrowingintheRSWprocessandarrayprocessingalgorithmbasedonacousticfieldcanextractcharacteristicparameterstoevaluateRSWquality.ItwasconcludedthattheacousticarraysensorsystemoffersanewmethodologyforRSWqualityinspection.

简介：Theresistancespotweldingof6063-716aluminumalloyandl6Mnsteelwasstudiedbynuggetalloying.TheresultsindicatedthattheAl-steeljointhadcharacteristicsofwelding-brazing.Thenuggetzoneconsistedmainlyofα-AlsolidsolutionwithdislocationsandfineMg_2Siparticles.Theinterfacezonehadadouble-layerstructure:Fe_2Al_5layeratsteelsideandFe_4Al_(13)layeratAlnuggetside.Thenuggetalloyinghasasignificanteffectonthejointpropertiesbychangingphasecompositionandrefinementofgrains.WhenalloyelementsCu,Zn,TiandNiwereadded,thetensileshearloadofAl-steeljointsreached2780N,2910N,2915Nand2929Nrespectively,whichincreasedby24.1%,29.9%,30.1%and30.7%respectivelycomparedwiththat(2241N)ofjointwithoutnuggetalloying.Therefore,itisaneffectivewayforimprovingmechanicalpropertiesofresistancespotweldedAl-steeljoints.

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简介：Weldabilityofpolyetheretherketone(PEEK)withpolyetherimide(PEI)istested.AndcarbonfiberreinforcedPEEKlaminatesareresistanceweldedusingstainlesssteelmeshheatingelement.Theeffectsoftheweldingtimeandweldingpressureonthelapshearstrengthofjointsareinvestigated.ResultsshowthatPEEKcanhealwithPEIwellinweldingconditionandthelapshearstrengthofPEEK/CF(carbonfibre)jointincreaseslinearlywithweldingtime,butreachesamaximumvaluewhenweldingpressurerangingfrom0.3MPato0.5MPawithconstantweldingtime.ThefracturecharacteristicsofsurfaceareanalyzedbySEMtechniques,andfourtypesoffracturemodesoflapshearjointsaresuggested.

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简介：EffectsofalloyelementsonthemicrostructureandcrackresistanceofFe-C-Crweldsurfacinglayerwereinvestigated.Theresultsshowthatmicrostructuresofthelayermainlyconsistofcarbidesandaustenitematrix.IncreasingCandCrcontentsimpairthecrackresistanceofthelayerduetoincreasedamountofbrittlecarbides.TheadditionofNi,NborMoimprovesthecrackresistanceofFe-C-CrweldsurfacinglayerbyincreasingtheamountofausteniteandformingfineNbCorM7C3carbidesinthelayer.But,theexcessiveNb(>2.50wt%)orMo(>1.88wt%)impairsthecrackresistanceofthelayer,whichhasrelationwithincreasedcarbidesorcarbidecoarseningandaustenitematrixsolidsolutionstrengthening.ThepropercombinationofC,Cr,Ni,NbandMocanfurtherimprovenotonlythecrackresistanceofFe-C-CrweldsurfacinglayerbutalsotheerosionresistanceasaresultoffineNbCandM7C3carbidesdistributinguniformlyinaustenitematrix.Theoptimallayercompositionsare3.05wt%C,20.58wt%Cr,1.75wt%Ni,2.00wt%Nband1.88wt%Mo.

简介：Anaxisymmetricfiniteelementmodelisdevelopedtosimulatethetemperaturefieldofresistantspotweldingaccordingtotheprocesscharactersofnuggetformationofnon-equalstainlesssteelsheets.Asimulationmethodoftheinteractionofelectricalandthermalfactorsispresented.Thespotweldingprocessofnuggetformationissimulatedusinghardandsoftweldingtechniquenorms.Theheatingcharactersofsoftandhardnormsdeterminethedifferencesintheprocessofnuggetformationanddeterminethefinallyshapeandoffsetofnugget.Experimentalverificationshowsthatthemodelpredictionagreeswellwiththepractical.