简介:有五个分支的像花瓣的icosahedralquasicrystal,被认为是icosahedralquasicrystal的代表性的形态学,在Y富有的Mg-Zn-Y第三的合金被观察了。而且,像多角形的形态学,icosahedralquasicrystal的另一个模式,也在Y富有的Mg-Zn-Y第三的合金被发现了。后者形态学源于以前的进化。icosahedralquasicrystal的像花瓣的形态学的生长机制也被讨论。Alloying作文,即,Y元素内容,是导致icosahedralquasicrystal的形态学进化的一个主要因素。
简介:ElectrodeProcessofY(Ⅲ)onNickelElectrodeandSurfaceMetallizingZhouChungen(周春根)(UniversityofAeronauticsandAstronauticsBeijing,Be...
简介:EnthalpyofReactionsinY-Ba-Cu-OSystemShaWei沙维(Departmentof.MaterialsScienceandMetallurgy,UniversityofCambridge.U.K.)Received17...
简介:ThispaperdealswiththestructureoftheY^Ⅲcomplexwithaminopolycarboxylicacids,synthesisandstructuraldeterminationofthecomplex(NH4)[YⅢ(edta)(H2O)3]·3H2O(edta=ethylenediaminetetraaceticacid).Thecrystalandmolecularstructuresofthe(NHO[YⅢ(edta)(H2O)3]·3H20complexhavebeendeterminedbysingle-crystalX-raystructureanalysis.Thecrystalofthecomplex(NH4)[YⅢ(edta)(H2O)3]·3H2Obelongstoorthorhombiccrystalsystemandfdd2spacegroup.Thecrystaldataareasfollows:a=1.9441(9)nm,b=3.5459(18)nm,c=1.2196(6)nm,V=8.407(7)nm3,Z=16,M~=503.25,Dc=1.590g.cm3,μ=2.844mm-1andF(000)=4160.ThefinalRandRware0.0486and0.1332for3388(I>2σ(I))uniquereflections,respectively.Thecomplexanion[YⅢ(edta)(H2O)3]hasapseudo-mono-cappedsquareantiprismaticnine-coordinatestructureinwhichthesixcoordinateatoms(twoNandfourO)arefromanedtaligandandthreewatermoleculescoordinatetothecentralYⅢiondirectly.Fromtheresultsitcanbepredictedthattheymioncanalsoformanine-coordinatecomplexwithttha(=triethylenetetraminehexaaceticacid)ligand,sotheradioactivecomplexanion[99YⅢ(Httha)]2-cansupplyafreecarboxylgroup(-CH2COOH)beingusedformolecularembellishmenttoformtheTDDSforthetreatmentofcancers.
简介:作为La-Mg-Y系统的一个例子,方法怎么建立单个阶段的热力学的模型在热力学的优化的过程被介绍。答案阶段(液体,以身体为中心立方,以脸为中心立方、包装hexagonalclose、双六角形拥挤不堪)与Redlich-Kister方程被建模。Thecompound精力模型被用来在La-Mg-Y系统描述金属间化合的混合物的热力学的函数。在La-Mg-Y系统的混合物Mg_2Y,Mg_(24)Y_5,Mg_(12)La,Mg_(17)La_2,Mg_(41)La_5,Mg_3La和Mg_2La被当作公式(Mg,Y)_2(La,Mg,Y),Mg_(24)(La,Mg,Y)_4Y,Mg_(12)(La,Y),Mg_(17)(La,Y)_2,Mg_(41)(La,Y)_5,Mg_3(La,Mg,Y)并且Mg_2(La,Y)分别地。一个模型(La,Mg,Y)_(0.5)(La,Mg,Y)_(0.5)被使用由MgLa和MgY描述复合MgMformed以便在La-Mg-Y系统与CsCl类型结构(B2)应付在body-centeredcubic答案(A2)和MgM之间的顺序混乱转变。单个阶段的吉布斯精力在La-Mg被优化,躺并且由CALPHAD的La-Mg-Y系统技术。液体的Theprojection我们为La-Mg-Y系统的表面被预言。包括Mg,艾尔,Cu,Ni,Mn,Zn和稀土元素形成的36二进制代码和15三元系统的基于Mg的合金数据库元素在SGTE被安装标准。
简介:采用电导率、显微硬度、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究Al-0.30Zr与Al-0.30Zr-0.08Y合金的微观组织与性能。铸态Al-Zr-Y合金中微米尺度初生Al3Y相通过共晶反应在晶内和晶界上同时生成。在Al-Zr-Y合金中,Y明显加速了Al3Zr(Ll2)的析出动力学。由于较大体积Al3(Zr,Y)析出相的生成,Al-Zr-Y合金的电导率明显高于Al-Zr合金的。在Al-Zr-Y合金中观察到了高密度的弥散球状Ll2结构Al3(Zr-Y)析出相。Al-0.30Zr-0.08Y合金具有比Al-0.30Zr合金更强的抗再结晶能力。
简介:Todevelopanewmagnesiumalloywithexcellentformabilityatroomtemperature,theeffectofY,Ce,andGdadditionontextureandstretchformabilityofMg–1.5Znalloyswascarriedout.TheresultshowsthatY,Ce,andGdadditioninMg–1.5Znalloyscaneffectivelyweakenandmodifythebasalplanetexture,characterizedbyTD-splittextureinwhichthepositionofbasalistitledfromnormaldirection(ND)towardtransversedirection(TD).WhenMg–1.5ZnalloywithGdadditionappearslowtextureintensityandTD-splittexture,wherethepositionofbasalpolesistiltedbyabout±35°fromNDtowardtoTD,thelargestErichsenvalueof7.0andtheelongationratereaches29.1%inTDdirection.However,YandCeadditioninMg–1.5Znalloyspromotealargenumberofsecondphaseparticles,whichcancelthecontributionoftheuniquebasaltexturetostretchformabilityandductility.
简介:ThemixturemodelofAl85Y4Nd4Ni7alloyinwhichapartiallycrystallizedamorphousalloyisregardedasananocompositeofanAlnanoparticleandaremainingamorphousmatrixispresented.Itsevolutionintheprocessofcrystallizationhasbeeninvestigatedbydifferentialscanningcalorimetry(DSC),X-raydiffraction(XRD),andtransmissionelectronmicroscopy(TEM).Mainlyamorphousstructurewithα-Alnanocrystalsembeddedintheamorphousmatrixhasbeenrevealedbymeltspiningthealloy.Crystallizationisshowedtooccurinthreestages:(1)crystallizationofamorphousalloyandformationofAlNiY,AlNdNiandunknowncrystallinephases,(2)formationofAl3YandAl3Nd,and(3)formationofAl3Ni.
简介:Mg-7.22Gd-4.84Y-1.26Nd-0.58Zr(GWN751K)镁合金的行为发展在热变丑过程期间被讨论。在0.002~2.000s的紧张率范围上的镁合金的流动压力行为?1并且在623~773的温度范围,K在60%的最大的变丑度下面在一个Gleeble-1500D热模拟器上被学习。试验性的结果证明在应力和紧张之间的关系被紧张率和变丑温度显然影响。GWN751K镁合金的流动压力能被Zener-Hollomon参数在夸张Arrhenius类型方程在高温度变丑期间代表。压力代表n和变丑激活精力Q被线性回归分析评估。压力代表n被适合是3.16。合金的热变丑激活精力在热变丑期间是230.03kJ/mol。热变丑的微观结构被紧张率和压缩温度也强烈影响。合金能与0.2=的机械性质在723K被渗出,这被发现260MPa,b=320MPa,和=18%。
简介:研究Cu-Mg-Te-Y合金在铸态、热轧态、冷轧态的组织和元素分布;讨论不同退火温度对Cu-Mg-Te-Y合金组织的改变;分析轧制和退火温度对Cu-Mg-Te-Y合金性能的影响。结果表明,不同的轧制工艺获得的合金组织与铸态合金组织相比差别明显,轧制后合金中Mg元素分布比铸态合金的更加均匀,Cu-Mg-Te-Y合金热轧后Cu2Te相被挤碎,尺寸变小,分布更加弥散,继续冷轧后Cu2Te相则被拉长、压扁,呈细条状。冷轧后的Cu-Mg-Te-Y合金在390℃以下退火1h,组织变化不明显,在550℃退火1h后,冷变形产生的纤维状组织发生完全回复再结晶,加工硬化效果消失,抗拉强度大幅度下降,导电率上升。退火温度在360~390℃范围内,Cu-Mg-Te-Y合金可以获得较好的力学性能。
简介:Mg–9Li–3Al–1.6Yalloyswerepreparedthroughmixturemethod.Themicrostructure,mechanicalproperties,andcorrosionresistanceoftheas-castandasextrudedalloyswerestudiedbyopticalmicroscopy(OM),scanningelectronicmicroscopy(SEM),X-raydiffraction(XRD),mechanicalpropertiestesting,andelectrochemicalmeasurement.Theas-castMg–9Li–3Al–1.6Yalloywiththeaveragegrainsizeof325lmiscomposedofb-Limatrix,blocka-Mg,andgranuleAl2Yphases.Afterextrusion,thegrainsizeoftheas-castalloyisobviouslyrefinedandreachesto75lm;thestrengthandelongationoftheextrudedalloyareenhancedby17.20%and49.45%,respectively,owingtotheirfinemicrostructureandreductionofcastingdefects.Theas-extrudedalloyshowsbettercorrosionresistancecomparedtotheas-castone,whichmayberelatedtothelowstoredenergyanddislocationdensityintheextrudedalloy,alsothehomogenizationtreatmentbeforeextrusion.
简介:AnexperimentalMg97Zn1Y2(molarfraction,%)alloywasproducedbyrollingtheas-castalloy.Themicrostructureofthealloyiscomposedoftheα-Mg(alsomarkedas2H-Mgwithreferencetolong-periodstackingstructureaccordingtohexagonalclosepackedstructure)andlong-periodstacking(LPS)phase.TensiletestsofMg97Zn1Y2alloyincomparisonwithpureMgwereconducted.Thefracturemorphologiesofthetensilespecimenswerecharacterizedandthemicrostructuresnearfracturesurfacewereobserved.TheresultsshowthattherolledMg97Zn1Y2alloyshowsamixedfracturemodeincludingdimplesindicatingaductilefracturepatternandasmallfractionofcleavageplanesindicatingabrittlefracturepattern,whichisdifferentfromthesinglebrittlefractureoftheas-castalloy.Inaddition,theplasticdeformationismainlyfromdislocationsinducedstrainwithsmallstrengtheningeffectduringplasticdeformationintheas-castMg97Zn1Y2alloy,andthestrainhardeningrateissimilartothatoftheas-castpuremagnesium.ThedeformationmechanismofMg97Zn1Y2alloyisdifferentfromthatofthepuremagnesiumaccordingtoametallographicalobservationthatwhethertwinsarefoundornot.ThestrengtheningeffecthardlyexistsintherolledMg97Zn1Y2alloyunderthesamedislocationsinducedstrain,whichisdifferentfromthatoftheas-castalloywithmoderatestrengtheningeffect.
简介:TheslidingfrictionandwearbehaviorsofMg–11Y–5Gd–2Zn–0.5Zr(wt%)alloywereinvestigatedunderoillubricantconditionbypin-on-diskconfigurationwithaconstantslidingdistanceof1,000minthetemperaturerangeof25–200°C.Resultsindicatethatthevolumetricwearratesandaveragefrictioncoefficientsdecreasewiththeincreaseofslidingspeeds,andincreasewiththeincreaseoftesttemperaturebelow150°C.ThehardandthermallystableMg12(Y,Gd)Znphasewithlong-periodstackingorderstructureinthealloypresentssignificantwearresistance.Thewearmechanismbelow100°Cisabrasivewearasaresultofplasticextrusiondeformation.Thecorporateeffectsofsevereabrasive,oxidative,anddelaminatingwearresultinthetribologicalmechanismabove100°C.
简介:Anewseriesofrareearthcompounds,Y2-xErxMo4O15(x=0.0-2.0),weresynthesizedandtheirstructuresweredeterminedbypowderX-raydiffraction(XRD).RietveldanalysisofXRDpatternsrevealsthatthecompoundsofthisseriescrystallizeinmonoclinicsystemwithspacegroupP21/c.Thelatticeparametersa,b,c,βandtheunitcellvolumeVde-creaselinearlywithincreasingErcontent.Thethermalexpansionpropertiesofthesecompoundswerestudiedunderhigh-temperatureXRD.PositivethermalexpansionsofcompoundsY2-xErxMo4O15arefoundtobeanisotropicalongthethreecrystallographicdirectionswhereaandcaxesexpandwhilebaxiscontractsinthewholetemperaturerange.Byanalysisofdata,theexpansionofweakbandMo2-O14withrisingtemperatureshouldberesponsibleforpositivethermalexpansion.
简介:基于热分析结果,对AM50-4%(Zn,Y)(Zn/Y摩尔比为6:1)合金设计并实施一种两步递进固溶处理。利用OM、XRD、SEM/EDS、TEM、拉伸实验和硬度实验研究固溶与时效处理对AM50-4%(Zn,Y)合金组织与力学性能的影响。结果表明:与一步固溶处理相比,两步递进固溶处理能够使Φ和β相充分溶解于基体,获得更高的溶质过饱和度,从而一定程度上增强合金在后续时效处理中的弥散强化效果。在180℃进行时效处理时,Φ相析出对合金综合力学性能的影响要大于β相。经两步递进固溶处理(345℃,16h+375℃,6h)的AM50.4%(Zn,Y)合金在时效处理(180℃,12h)后获得峰时效强度。