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简介：ThispaperintroducesabrazingprocessbetweenAl_2O_3ceramicandInvaralloy.Al_2O_3canbebrazedwithInvareffectively.TheinterfacialstructureofAl_2O_3/Invarjointcanbeexpressedas:Invar/Ag(s,s)+Cu(s,s)+Fe_2Ti(zoneⅠ)/Ag(s,s)+Cu(s,s)+Fe_2Ti+NiTi+Cu_3Ti(zoneⅡ)/Ag(s,s)+Cu(s,s)+Cu_2Ti+Al(s,s)+TiC+TiO(zoneⅢ)/Al_2O_3.Themaximumshearstrengthof139MPawasmeasuredforas-brazedAl_2O_3/Invarjointbrazedat850℃for25minor900℃for15min.

简介：TheCu/Sn-3.OAg-0.5Cu/Cubuttingsolderjointswerefabricatedtoinvestigatetheevolutionoftheinterfacialintermetalliccompound(IMC)andthedegradationofthetensilestrengthofsolderjointsundertheeffectofelectromigration(EM)andagingprocesses.Scanningelectronmicroscopy(SEM)resultsindicatedthattheCu_6Sn_5interfacialIMCpresentedobviousasymmetricalgrowthwiththeincreaseofEMtimeundercurrentdensityof1.78×10~4A/cm~2at100℃,andthegrowthofanodicIMCpresentedaparabolicrelationshipwithtimewhilethecathodicIMCgotthinnergradually.However,asforagingsamplesat100℃withoutcurrentstressing,theCu_6Sn_5IMCpresentedasymmetricalgrowthwithaslowerratethantheanodicIMCofEMsamples.Thetensileresultsindicatedthatthetensilestrengthofthesolderjointsundercurrentstressdeclinedmoredrasticwithtimethantheagingsamples,andthefracturemodetransformedfromductilefracturetobrittlefracturequicklywhilethefracturemodeofagingsamplestransformedfromcup-coneshapedfracturetomicroporousgatheringfractureinaslowway.

简介：Ni-basedsuperalloyK465isbrazedwithBNi-2fillermetalbyvacuumelectronbeambrazing(VEBB).InprocessofVEBB,effectsofprocessingprimaryparametersonshearstrengthofjointsareinvestigated.MicrostructureofthebrazedjointwithBNi-2fillermetalisstudiedbymeansofscanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS)andX-raydiffraction(XRD).TheresultsshowthatthestructureofbrazedseamconsistsofalargeamountofNi-basedγsolidsolution,Ni3Al(γ′),Ni3B,WB,CrB,andasmallquantityofWC,NbC.Themaximumshearstrengthofthejointis398MPawhenthebeamcurrentofweldingis2.6mA,heatingtimeis480sandfocusedcurrentis1800mA.

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简介：Themechanicalproperties,creepdamage,creeprupturestrengthandfeaturesofinterfacialfailuresofweldedjointsbetweenmartensite(SA213T91)andpearlitesteel(12Cr1MoV)havebeeninvestigatedbymeansofargontungstenpulsedarcwelding,hightemperatureacceleratedsimulation,creeprupture,mechanicalpropertytestsandscanningelectronicmicroscope(SEM).Theresearchresultsindicatethatthemechanicalpropertiesofovermatchedandmediummatchedjointdeteriorateobviously,andtheyaresusceptibletocreepdamageandfailureafteracceleratedsimulationoperation500h,intheconditionofpreheat250℃,andpostweldingheattreatment750℃×1h.However,themechanicalpropertiesofundermatchedjointarethebest,theinterfacialfailuretendencyofundermatchedweldedjointislessthanthoseofmediumandovermatchedweldedjoint.Therefore,itisreasonablethatlowalloymaterialTR31isusedasthefillermetalofweldbetweenSA213T91and12Cr1MoVsteel.