简介：BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope（SEM）,electron.probemicroanalysis（EPMA）andX-raydiffraction（XRD）.theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.

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：ThedistributionsoftheaxialstressandshearstressinAl2O3-TiC/Q235diffusionbondedjointswerestudiedusingfiniteelementmethod(FEM).Theeffectofinterlayerthicknessontheaxialstressandshearstresswasalsoinvestigated.Theresultsindicatethatthegradientsoftheaxialstressandshearstressaregreatnearthejointedge.ThemaximalshearstressproducesattheinterfaceoftheAl2O3-TiCandTiinterlayer.WiththeincreaseofCuinterlayerthickness,themagnitudesoftheaxialstressandshearstressfirstdecreaseandthenincrease.Thedistributionoftheaxialstresschangesgreatlywithalittlechangeintheshearstress.TheshearfractureinitiatesattheinterfaceoftheAl2O3-TiC/TiinterlayerwithhighshearstressandthenpropagatestotheAl2O3-TiCside,whichisconsistentwiththestressFEMcalculatingresults.

简介：Metallurgicalmodelingofsynergisticmicrocrackself-repairmenduringweldingsinglecrystalandpolycrystallinesuperalloysofhigh-temperatureaerospacematerialshasbeenproperlyestablished.Theideaofimprovementofnickel-basedsuperalloysweldabilitythroughnon-equilibriumsolidificationbehaviorofbackfilltoself-repairarterialcracknetworkisusefullyproposed.Crystallographiccontrolstrategyofcrackself-repairmenoffusionzoneinterdendriticsolidificationcrackingandheat-affectedzone(HAZ)intergranularliquationcrackingistechnicallyachievable,indicatingthatoptimalniobiumalloyingbeneficiallyrefinesweldmicrostructure,stabilizestheprimarysolidificationpath,increasesthesolidificationtemperatureandconcomitantlydecreasestheweldpoolgeometry.High-carbongrainboundaryismorethermalstableandlesscontributestoincipientintergranularliquidfilmthanthatoflow-carbongrainboundary.Thetheoreticalpredictionsofcrackingsusceptibilityareindirectlyverifiedinarathersatisfactorymanner.Additionally,themetallurgicalmodelingenhancespredicativecapabilitiesandtherebyisreadilyapplicableforotheralloysystems.

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简介：1999年由TWI代表国际搅拌摩擦焊专利协会，在美国加利福尼亚成功举办第一届搅拌摩擦焊国际会议，此后，每两年一届分别在不同国家成功举办了九届搅拌摩擦焊国际会议。