Microstructure - properties relationship of transient liquid phase diffusion bonded a third generation single crystal super alloy joint

(整期优先)网络出版时间:2017-01-11
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Microstructureoftransientliquidphase(TLP)diffusionbondedathirdgenerationsinglecrystalsuperalloyjointwasinvestigatedusingscanningelectronmicroscopy(SEM),andmechanicalpropertiestestofjointwascarriedout,forobtainingrelationshipbetweenmicrostructureandmechanicalpropertiesofjoint.Theresultsshowedthatthejointcontainedbondingzoneandbasemetal.Thediffusionzonewasobviouslyobserved.Whenitwasnotfinishedforisothermalsolidificationprocess,thebondingzonewouldcontainisothermalsolidificationzoneandrapidsolidificationzone.Metallographicexaminationrevealedthatisothermalsolidificationzonewasconsistedofyandphase.Rapidsolidificationzonewasconsistedoftwodifferentstructures,whichwereternaryeutecticofborides,yandy,phasedevelopingattheedgeofjoint,binaryeutecticofyandphaseappearingintheportionofjoint.Whenitwasnotenoughforhomogenizationprocessundertheconditionoffinishingisothermalsolidificationprocess,thebondingzonewouldcontainisothermalsolidificationzoneandboridesattheinterface.Undertheconditionsofrelativelyhighweldingtemperatureandlongweldingtime,averagetensilestrengthofjointwasequivalenttothatofparentmaterial.