学科分类
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17 个结果
  • 简介:Theelevatedtemperaturetensileexperimentshavebeencarriedoutonthemagnesiumalloyandresultsindicatethatthemagnesiumalloyhasexcellentsuperplasticproperty.Gleebe-1500testingmachinewasusedinthediffusionbondingexperimentonthesuperplasticmagnesiumalloy.Then,theshearstrengthofthejointsunderdifferentconditionsisobtainedthroughsheartestingandtheoptimumprocessingparametersforthediffusionbondingareachieved.Bymetallurgicalmicroscopeandscanningelectronmicroscope(SEM),itisrevealedthatthemicromechanismofdiffusionbondingistheslideofgrainboundariescausedbythegrowthofgrainsandatomdiffusionofthesuperplasticmagnesiumalloy.

  • 标签: 超塑性镁合金 扩散结合 微观结构 剪切应力
  • 简介:TheZrcoatingwasdepositedontitaniumsurfaceusingthemagnetronsputteringtechnique.EffectsofZrcoatingonmicrostructureandmechanicalpropertiesofporcelainfiredtotitaniumhavebeeninvestigated.Theresultsshowthatinterdiffusionofelementsoccursduringporcelainfiring,andtheZrcoatingcaneffectivelyprotecttitaniumsurfacefromexcessoxidation.ThestrengthofbondzonewithZrcoatingdepositedfor1hourreaches29.7MPa,whichhasincreasedby26.4%ascomparedwiththatofbondzonewithoutcoating(23.5MPa).

  • 标签: 瓷器 锆涂层 焊接强度
  • 简介:Thevacuumdiffusionbondingoftitaniumalloytotin-bronzehasbeenstudiedandthefeasibilityandappropriateprocessingparametershavebeeninvestigated.Themaximumtensilestrengthofthejointsis168MPa,andafirmjointisobtained.ThemicrostructureofdiffusionbondedjointhasbeenobservedbySEM.X-rayandEPMA,andthemainfactorsaffectingdiffusionbondinghavebeenanalyzed.TheintermetalliccompoundsTi2CuandTiCuwereformedneartheinterface.Thewidthandquantityoftheintermetalliccompoundincreaseswiththeincreaseofthebondingtime.Theformationoftheintermetalliccompoundsresultsinembrittlementofthejointandthepoorjointproperties.

  • 标签: 钛合金 锡青铜合金 扩散结合
  • 简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.

  • 标签: ALUMINA active BRAZING INTERFACIAL reaction joint
  • 简介:Theliquid-filmsolution-diffusionbondingofZCuBe2.5alloyswasconductedusingCu-basedalloypowders.Thetensilestrengthofthebondingtimedecreasesandtheinterfacemigrationvelocityincreasesbondingtime,thethicknessofdiffusionlayerincreaseswiththeincreaseoftemperaturegradient,andthistendencybecomesmoreremarkablewiththeprolongingofbondingtime.

  • 标签: 扩散焊接 温度梯度 压焊时间 液态膜 铜合金
  • 简介:DD6alloywasbondedbytransientliquidphase(TLP)diffusionbonding.Themaincompositionsoftheinterlayeralloyemployedweresimilartothoseofthebasemetal,DD6,andacertainamountofelementBwasaddedasthemeltingpointdepressant.Theresultsshowthatitisdifficulttoobtainthejointswiththemicrostructurescompletelyhomogeneous.ForthejointTLPdiffusionbondedat1290℃for12h,abouthalfareasofthebeampossessedαγ+γ′microstructure,nearlyidenticalwiththatofthebasemetal,andtheotherlocalareasconsistedofT-solution,borides,etc.Prolongingthebondingtimeto24h,theinhomogeneousareasinthejointreduced,andthejointpropertyimproved.Thejointstress-rupturestrengthat980℃and1100℃reached90%-100%and70%-80%ofthoseofthebasemetalrespectively.

  • 标签: 简单晶体 超合金 液态相变换 结合扩散 接缝应力-破裂性质
  • 简介:Dynamicsinpartialtransientliquidphasebonding(PTLPbonding)ofSi3N4ceramicwithTi/Cu/Timulti-interlayerwassystematicallystudiedthroughmicro-analysisofjointinterfaces.Theresultsshowthatgrowthofreactionlayerandisothermalsolidificationprocessiondoatthesametime.GrowthofreactionlayerandmovingofisothermalsolidificationinterfaceobeytheparaboliclawgovernedbythediffusionofparticipatingelementsduringthePTLPbonding.Coordinationoftheabovetwodynamicsprocessisdonethroughtimeandtemperature.Whenreactionlayerthicknessissuitableandisothermalsolidificationprocessisfinished,thehighbondingstrengthatroomtemperatureandhightemperatureareobtained.

  • 标签: 部分液体相连接 氮化硅瓷 等温凝固 动力学 反应层
  • 简介:Inthisstudy,atwo-stepheatingprocessisintroducedfortransientliquidphase(TLP)diffusionbondingforsoundjointswithT91heatresistantsteels.Atfirst,ashort-timehighertemperatureheatingstepisaddressedtomelttheinterlayer,followedbythesecondsteptocompleteisothermalsolidificationatalowtemperature.Themostcriticalfeatureofournewmethodisproducinganon-planarinterfaceattheT91heatresistantsteelsjoint.WeproposeatransitionalliquidphasebondingofT91heatresistantsteelsbythisapproach.Sincejointmicrostructureshavebeenstudied,wetestedthetensilestrengthtoassessjointmechanicalproperty.Theresultindicatesthatthesolidifiedbondmaycontainaprimarysolid-solution,similarcompositiontotheparentmetalandfreefromprecipitates.Jointtensilestrengthofthejointisnotlowerthanparentmaterials.Jointbend'sstrengthsareenhancedduetothehighermetal-to-metaljunctionproducinganon-planarbondlines.Nevertheless,thetraditionaltransientliquidphasediffusionbondingproducesplanarones.Bondingparametersofnewprocessare1260℃for0.5minand1230℃for4min.

  • 标签: 液相扩散焊 T91钢 工艺 焊接接头 瞬时 等温凝固
  • 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.

  • 标签: 钴基耐高温合金 两步过渡液相扩散焊 中间层合金 硬度
  • 简介:SolderingofLD31aluminumalloysusingSn-PbsolderpasteafterelectricbrushplatingNiandCucoatingswasnvestigated.ThetechnologyofelectricbrushplatingNiandCuwasstudiedandplatingsolutionwasdeveloped.Themicrostructureofthecoatings,solderedjointandfracturefacewereanalyzedusingopticmicroscopy,SEMandEDX.Theshearstrengthofsolderedjointcouldreachashighas26.83MPa.Theresultsshowedthatreliablesolderedjointcouldbeobtainedat230℃,theadhesionofcoatingsandLD31aluminumalloysubstratewashighenoughtobearthethermalprocessinthesoldering.

  • 标签: ld31铝合金 电刷电镀 低温焊接
  • 简介:Microstructuresandmechanicalpropertiesoftransientliquidphase(TLP)bondedmagnesiummetalmatrixcomposite(MMC)jointsusingcopperinterlayerhavebeeninvestigated.Withanincreaseofbondingtimesfrom5minto50minatbondingtemperatureof510℃,theaverageconcentrationofcopperinthebondedzonedecreased,themicrostructureinthezonechangedfromCu,α-MgandCuMg2toα-Mg,CuMg2andTiC,andmechanicalpropertiesofthejointincreased.Theshearstrengthofthejointbondedat510℃for50minreached64MPaduetothemetallurgicalbondingofthejointandimprovingitshomogeneityofcompositionandmicrostructure.ItisfavorabletoincreasethebondingtimeforimprovingmechanicalpropertiesofTLPbondedmagnesiumMMCjoint.

  • 标签: 碳化钛颗粒增强 镁金属基复合材料 过渡液相扩散焊 显微结构 力学性能