Microstructureoftransientliquidphase(TLP)diffusionbondedathirdgenerationsinglecrystalsuperalloyjointwasinvestigatedusingscanningelectronmicroscopy(SEM),andmechanicalpropertiestestofjointwascarriedout,forobtainingrelationshipbetweenmicrostructureandmechanicalpropertiesofjoint.Theresultsshowedthatthejointcontainedbondingzoneandbasemetal.Thediffusionzonewasobviouslyobserved.Whenitwasnotfinishedforisothermalsolidificationprocess，thebondingzonewouldcontainisothermalsolidificationzoneandrapidsolidificationzone.Metallographicexaminationrevealedthatisothermalsolidificationzonewasconsistedofyandphase.Rapidsolidificationzonewasconsistedoftwodifferentstructures,whichwereternaryeutecticofborides,yandy,phasedevelopingattheedgeofjoint,binaryeutecticofyandphaseappearingintheportionofjoint.Whenitwasnotenoughforhomogenizationprocessundertheconditionoffinishingisothermalsolidificationprocess,thebondingzonewouldcontainisothermalsolidificationzoneandboridesattheinterface.Undertheconditionsofrelativelyhighweldingtemperatureandlongweldingtime,averagetensilestrengthofjointwasequivalenttothatofparentmaterial.
