简介:Inthisstudy,adoptinguniformdesignmethodestablishedamathematicalmodeltopreparemulti-elementactiveflux.GHA\69superalloyplateswereweldedbytheNd:YAGlaserequipmentwiththepreparedactiveflux.Theresultsshowallkindsoffluxesincreasethedepthtowidthratioandthemulti-componentsystemsaremoresignificant.Thelargestincrementofthewelddepthtowidthratiois159%,obtainedbyusingoftheFI2seriesflux.Itisprovedthatbyusingoftheactivefluxtoincreasethedepthtowidthratioofmicrolaserweldingisfeasible.
简介:γ'PrecipitationinanOxideDispersion-StrengthenedNi-BaseSuperalloyShaWei(沙维)(DepartnientofMaterialsScienceandMetalurgy,Universi...
简介:TheeffectofrareearthelementyttriumonthehightemperatureoxidationresistanceofadirectionallysolidifiedNi-basesuperalloywasstudiedwithscanningelectronmicroscopy(SEM),energydispersivespectrum(EDS)andX-raydiffraction(XRD)techniques.Theresultsshowthattheoxidationresistanceofthealloyissubstantiallyimprovedbyaddingproperamountofyttrium.
简介:Theeffectofsolidificationrateonthemicrostructuredevelopmentofnickel-basedsuperalloyunderthetemperaturegradientof500K·cm-1wasstudied.Theresultsshowthat,withtheincreaseofdirectionalsolidificationratefrom50to800μm·s-1,boththeprimaryandthesecondarydendritearmspacingsofthealloydecreasegradually,andthedendritemorphologiestransformfromcoarsedendritetosuperfinedendrite.Thesizesofallprecipitatesinthesuperalloydecreasegradually.Themorphologyof...
简介:IN690superalloy的热变丑行为在12731473K的一个温度范围和0.0110s的一个紧张率范围被描绘?1使用的单轴的压缩测试在上处理退火的材料。在流动应力和有效紧张,有效紧张率以及变丑温度之间的组成的关系被学习。流动显著地与IN690superalloy增加的变丑温度强调还原剂,这能被结束。而,当紧张率从0.1s增加时,有流动应力的重要增加?1~10s?1。基于夸张正弦的Arrhenius类型方程,就紧张的赔偿而言的一个组成的方程被开发。当变丑紧张增加,激活精力和材料常数(Q,n和lnA)减少。紧张依赖者术语成功地通过一个四次的方程在组成的方程被合并。在试验性的数据和预言的结果之间的一个好协议被完成了,显示建议组成的方程和材料常数是的determing的方法对模型合适IN690superalloy的高温度变丑行为。
简介:CharacterisationofaMechanicallyAlloyedOxideDispersionStrengthenedNiekel-baseSuperalloyShaWei(沙维)DepertmentofMaterialsSciencea...
简介:TheeffectoffrequencyandsampleshapeonfatiguebehaviorsofDZ125superalloyaresystematicallystudied.Theresultsshowthatfatiguefracturestilloccursabovethecycleof10~8fortestscarriedoutatthefrequencyoff=20kHzandstressratioR=-1,sothetraditionalfatiguelimitatcycleof10~7isnotappropriateforfatiguedesign.Fatiguefracturesurfacesareperpendiculartostressaxisforcylindricalandplatespecimens,andthefatiguecracksoriginatefromtheextrasurfaceofthespecimens.Fatiguecrackisapttopropagatefromcuttingdirectiontoforwarddirection,whichoccursmainlyinthesecondpropagationstageathigherstressamplitude.ThereisanobviousfrequencyeffectforDZ125superalloy.Thehigherthetestfrequencyis,themoreserioustheeffectoffrequencyonfatiguebehaviorsofthealloy.Afterthefrequencycorrection,theultra-highcyclefatigueS-NcurvewellcoincidewiththetraditionalfatigueS-Ncurve.
简介:TheeffectofLaelementonthemechanicalpropertiesandconstitutionnearbygrainboundaryinaCo-basesuperalloyCo-22Ni-22Cr-14kduring760℃ageinghasbeeninvestigatedbyAESandmaterialtesting.ResultsshowthatelementLacanbeinastateofsolidsolutionandsegregatesmainlyatthevicinityofgrainboundaries.ThepriorsegregationofLaatomscanaffectsegregationbehaviourofotherelements,sothatexertsinfluenceonmicrostructureofthealloy,ParticularlyincreasingofLacontentcandecreasePconcentrationatthevicinityofgrainboundariesbutnotdecreaseSconcentration.StogetherwithLaproducecosegregationeffect.ThecontentofLahasnoobviouseffectonhightemperaturestrength.WhenthecontentofLacomesupto0.02wt-%,itcanobviouslyimprovethehightemperatureductility.
简介:RecrystalizationinOxideDispersionStrengthenedNickelbaseSuperaloyMA760ShaWei(沙维)DepartmentofCivilEnginering,TheQueen′sUnivers...
简介:Accordingtothespecificationofsuperalloy-stainlesssteelarcbrazingandcharacteristicofthebasemetal,abestfillermetalwhichhasrelativelowermeltingpoint,nicewettability,goodweldforming,andadequateshearstrengthwasresearched.TheexperimentresultsshowthatwettabilityofCuFeMnonthestainlesssteelisverypoor,concomitantwithamassofpurplesootduringtheweldingwhichdeterioratestheworkingcondition.CuSiMnhasthebestwettabilityonboththesuperalloyandstainlesssteel,butthereremainsalotofpitandslagonthesurfaceoftheweldbead.Copper-basedsolderhasthehighestmeltingpointanditswettabilityandclearancefillabilityareweakerthanCuSi3.WettabilityandclearancefillabilityoftheCuSi3arethebestinallthecandidatefillermetals,anditsweldissmoothnessandhashighershearstrength.Foritscomprehensiveability,CuSi3isselectedasthefinalfillermetal.
简介:Widegapbrazing(WGB)experimentsusingthebuttedspecimenwitha1.5mmgapwerecarriedoutfortherepairofthefailedK418Bsuperalloylow-pressureturbinevanes.Thehightemperaturecreeprupturestrengthsofthebrazedjointsweretested,andthemicrostructuresandfracturesurfacesofthejointswereobserved.TheresultsshowthatthemicrostructureofK418Balloyjointiscomposedofdenseequiaxedgrain,smallanddiscretecompoundswithafewmicro-pores.Duringthecreeprupturetest,thecracksinitiatepreferentiallyatthemicro-poreorthegrainboundary,thenpropagatealongthegrainboundarytillthefracturehappens.Thecreeprupturestrengthat700℃ofthebrazedjointswith50%brazemetalintheworkingpartcouldexceed90%thatoftheK418Bsuperalloy,andthejointswith100%brazemetalintheworkingpartachieve70%to80%ofthecreeprupturestrengthsfortheK418Bbasemetal.
简介:Thethermalprotectionperformanceofsuperalloyhoneycombstructureinhigh-temperatureenvironmentsareimportantforthermalprotectiondesignofhigh-speedaircrafts.Byusingaself-developedtransientaerodynamicthermalsimulationsystem,thethermalprotectionperformanceofsuperalloyhoneycombpanelwastestedinthispaperatdifferenttransientheatingratesrangingfrom5℃/sto30℃/s,withthemaximuminstantaneoustemperaturereaching950℃.Furthermore,thethermalprotectionperformanceofsuperalloyhoneycombstructureundersimulatedthermalenvironmentswascomputedfordifferenthighheatingratesbyusing3Dfiniteelementmethod,andacomparisonbetweencalculationalandexperimentalresultswascarriedout.Theresultsofthisresearchprovideanimportantreferenceforthedesignofthermalprotectionsystemscomprisingsuperalloyhoneycombpanel.
简介:基于镍的单个水晶superalloy与的低周期的疲劳(LCF)行为[001]取向在T0掳C的中间的温度和T0+的更高的温度被学习在10的经常的低紧张率下面的250掳C?3s?1在周围的空气。superalloy展出了依赖于温度并且使用紧张振幅的周期的紧张压缩不对称现象。破裂表面上的分析证明表面和表面下的扔micropores是主要裂缝开始地点。内部Ta富有的碳化物经常在所有标本被观察。骨折的二种不同类型被frac-togaphy建议。一种类型被模式描绘--我与一台用显微镜裂开在T0+的不平的表面250掳C。而在更低的温度T0C的另外的类型赞成了中的一个或几八面{111}飞机,与正常模式相对照--我生长模式典型地在低装载观察了频率(几Hz)。为二个裂开的模式的失败机制纬鈥?正在砍在T0+在矩阵和纬/纬鈥?接口在T0掳C和裂开的反对ned和矩阵猛抛250掳C。