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.