简介：Anewintelligentcontrolmetholforweldingpositionerispropsed.ApplyinganimprovedfuzzycontrollerandavariablePIDcontroller,atwo-modeintelligengcontroller(TMICC)isdsignedonbasisoffuzzylogicadnrules.Thesimulationandexperimentalresultsshowthatthiscontrolsystemcanobtainbetterdynamicandstaticcharacteristics.

简介：Aimingattheweldingconditionofspacecomplexseamisuncertainandtheintelligenceofweldingrobotisunideal,atwo-wheeledmobilerobotisdeveloped.Itnotonlyhasthecapacityofautonomousdecisionandavoidingobstacles,butalsocanflexiblymoveandstronglyadaptvariableenvironment.Thecompositionoftheweldingrobotisdescribedandthedynamicmodelisestablished.Thefeasiblecontrolstrategyandcontrolalgorithmisputforward.Thesimulationexperimentsofrealworldareconducted,theresultsaresatisfying.

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简介：Inthisstudy,atwo-stepheatingprocessisintroducedfortransientliquidphase(TLP)diffusionbondingforsoundjointswithT91heatresistantsteels.Atfirst,ashort-timehighertemperatureheatingstepisaddressedtomelttheinterlayer,followedbythesecondsteptocompleteisothermalsolidificationatalowtemperature.Themostcriticalfeatureofournewmethodisproducinganon-planarinterfaceattheT91heatresistantsteelsjoint.WeproposeatransitionalliquidphasebondingofT91heatresistantsteelsbythisapproach.Sincejointmicrostructureshavebeenstudied,wetestedthetensilestrengthtoassessjointmechanicalproperty.Theresultindicatesthatthesolidifiedbondmaycontainaprimarysolid-solution,similarcompositiontotheparentmetalandfreefromprecipitates.Jointtensilestrengthofthejointisnotlowerthanparentmaterials.Jointbend'sstrengthsareenhancedduetothehighermetal-to-metaljunctionproducinganon-planarbondlines.Nevertheless,thetraditionaltransientliquidphasediffusionbondingproducesplanarones.Bondingparametersofnewprocessare1260℃for0.5minand1230℃for4min.

简介：Anewtechnology,thetwo-steptransientliquidphasediffusionbonding(TLP-DB)technologyforcobalt-basedK640superalloy,wasinvestigated.Themethodconsistsofashort-timehightemperatureheatingtomeltinterlayerfollowedbyisothermalsolidificationofliquidphaseatalowertemperaturethanthatoftheconventionalTLP-DB.Theresultindicatesthatthetwo-stepTLP-DBcanreliablyproduceanidealjointwithuniformchemicalcomposition,whichissuperiortothejointweldedbyconventionalTLP-DBinmicrostructureandmechanicalproperties.Bondingparametersofnewprocessare1250℃for0.5hand1180℃for3h.Thehigh-temperaturetensilestrengthofthejointbytwo-stepTLP-DBreaches74%ofthatofthebasematerialonanequalbasis,butthehigh-temperaturetensilestrengthofthejointbyconventionalTLP-DBisonly58%ofthatofthebasematerial.

简介：TheanalysisofthemicrostructuralcharacterizationandphasecompositionofelectronbeamweldedjointzonesofTi-43Al-9V-0.3Yalloyhasbeendoneinthisstudy.TheweldedseamismainlycomposedofB2phase,thepartialγ+α2two-phaselamellarstructureandgranularγmphase.AndthelanthanonYexistedasYAl2phaseandservedasgrainrefined.Theimpactofdifferentcoolingratesonjointmicrostructure,fracturecharacteristicandtensilestrengthwereinvestigated.Thehighcoolingraterestrainedthestructuraltransformationandresultedintheorderingstructure.Thefractureofthejointwasbrittlecleavagefracturebecausetheorderingstructurewentagainstrestrainingthecrackpropagation.Withthedecreaseofcoolingrate,thetransformationamountsoflamellarstructureincreased,andthefracturepresentedthelayeredandcross-layeredcharacteristic.