简介:ThemorphologyandcrystallographyofphasesintheCu-0.12%Zralloywereinvestigatedbyscanningelectronmicroscope(SEM),transmissionelectronmicroscope(TEM),andhigh-resolutiontransmissionelectronmicroscope(HRTEM).Theresultsshowthattheas-castmicrostructureofCu–ZralloyismainlyCumatrixandeutecticstructurewhichconsistofCuandCu5Zrphaseswithafinelamellarstructure.Thedisk-shapedandplatelikedCu5Zrphaseswithfccstructurearefoundinthematrix,inwhichhabitplaneisparallelto{111}aplaneofthematrix.BetweenthecoppermatrixandCu5Zrphase,thereexistsanorientationrelationshipof[112]a||[011]Cu5Zr;(111)a||(111)Cu5Zr.ThespacestructuremodelofCu5Zrphasecanbeestablished.
简介:AZr-1.15wt%Cr-0.10wt%Fealloywasbeta-quenchedfrom1050℃toproduceasupersaturatedα′-phase,andthenheatedforvaryingtimesattemperaturesfrom650℃to760℃toprecipitateZr(CrFe)2.Athermoelectricpower(TEP)techniqueandtransmissionelectronmicroscopy(TEM)wereusedtomonitorthisprecipitationprocess.UsingtheJohnson-Mehl-Avramiequation,theTEPresultsandalineregressionmethod,theactivationenergyfordiffusionandthediffusioncoefficientofchromium(andFe)inα-Zrhavebeencalculatedover650℃~760℃.Thetemperaturedependenceofthediffusioncoefficient,DCr/α(cm2/s)isdescribedat650℃~760℃bytherelationshipformula.ThecoarseningoftheZr(CrFe)2particlesshowsat1/2dependenceofmeanparticlesizeonagingtime,t.Suchatimedependenceistypicalofcoarseningwhereatomtransferacrosstheinterfaceisrate-controlling.
简介:BulkZr55Al10Ni5Cu30metallicglassplateswithadimensionof85mm×35mm×4mmandacomplicatedplatewerefabricatedbyinjectingcastingmethodusingspongyzirconiumandindustrialpurityaluminum,nickelandcopperasrawmaterials.Itwasshownthattheholdingtimeofliquidmetalsatelevatedtemperatureshadagreatinfluenceontheoxygencontentoftheplatesduetothecontaminationresultingfromtheatmosphere.Increasingholdingtimeresultedintheincreaseofoxygencontentintheinjectedalloy.Theglasstransitiontemperaturesofthebulkmetallicglassplatesarehigherthanthatreportedintheliteratureandcrystallizationtemperatureislowerfortheonewithhigheroxygencontentatthesameheatingrate.Theextensionoftheundercooledliquidregion△Txreachingabout87Kis3Khigherthanthatpreviouslyreportedand26Khigherthanthatwithoxygencontentof0.076wtpctfortheonewithoxygencontentashighas0.065wtpct.Thereforetheoxygencontentofthealloyhasasignificantinfluenceontheglassformingabilityandthermalstabilityofbulkmetalglass.Itissuggestedthatdirectcorrelationbetweenhighglassformingabilityandlarge△Txisonlyvalidforawell-definedIowoxygenconcentrationorhastobereconsideredbyincorporatingoxygenasanadditionalalloyingelement.
简介:采用铸锭冶金法制备Al-Zn-Mg-Cu-Zr合金和Al-Zn-Mg-Cu-Zr-Cr-Pr合金,再对其进行均匀化退火(460℃/24h)、锻压、固溶处理—室温水淬及峰时效处理。用金相显微镜观察合金的显微组织,并测试其力学性能,研究复合添加Zr、Cr、Pr对Al-Zn-Mg-Cu超高强铝合金再结晶行为和力学性能的影响。结果表明,复合添加Zr、Cr和Pr可显著抑制Al-Zn-Mg-Cu合金在锻压后回复过程中的亚晶合并长大,使该合金在较高温度(490℃)以及高温长时保温(480℃固溶4h)情况下仍能保持细小的亚晶组织,从而提高合金的力学性能。复合添加Zr、Cr、Pr能使合金在490℃固溶1h后在T6状态下的抗拉强度提高约25MPa、屈服强度提高近30MPa。
简介:TheintermetalliccompoundZr1-xTixCowaspreparedanditssuitabilityforhydrogenstoragewasinvestigated.ThealloysobtainedbymagneticlevitationmeltingwiththecompositionofZr1-xTixCo(x=0,0.1,0.2and0.3,at.%)showsinglecubicphasebyX-raydiffraction.Asingleslopingplateauwasobservedoneachisothermal,andpressure-composition-temperature(PCT)measurementresultsshowthattheequilibriumhydrogendesorptionpressureofZr1-xTixCoalloyincreaseswithincreasingTicontent.Thedesorptiontemperaturesforsupplying100kPahydrogenareabout665,642,621and614KforZrCo,Zr0.9Ti0.1Co,Zr0.8Ti0.2CoandZr0.7Ti0.3Coalloy,respectively.RepeatedhydrogenabsorptionanddesorptioncyclesdonotgenerateseparatedZrCo,TiCoandZrH2phases,indicatingthatalloyshavegoodthermalandhydrogenstabilization.
简介:X-raydiffraction(XRD)anddifferentialscanningcalorimetry(DSC)wereemployedtoinvestigatetheinfluenceofNicontentonthecrystallizationofamorphousZr70Cu30-xNix(atomfrationin%)alloys,ExperimentalresultsshowthatwiththeNicontentincreasingtheactivationenergiesforcrystallizationofamorphousZr70Cu30-xNixalloysincreasecorrespondingly,indicatingthatthethermalstabilityisgreatlyimproved.AlltheDSCtracesofamorphousZr70Cu30-xNixalloysexhibittwoexothermicpeaks,suggestingthatthecrystallizationprocessviaadouble-stageticles,whilethesecondonecorrespondstotheprecipitaionofnano-scaleZr2Niphaseandcrystallizationofresidualamporphousphase,ThemechanismonthecrystallizationofamorphousZr70Cu30-xNixalloyswasdiscussed.
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简介:基于Mg的氢存储合金MgNi,Mg0.9Ti0.1Ni,和Mg0.9Ti0.06Zr0.04Ni成功地借助于机械alloying(麻省)被准备。结构和这些基于Mg的材料的电气化学的特征被学习。X光检查衍射(XRD)结果证明合金的主要阶段展出非结晶的结构。扫描电子显微镜学(SEM)相片证明Ti和Zr的粒子尺寸代替了合金是在直径的大约24m。合金的周期生活被增加Ti和Zr延长。在50个费用分泌物周期以后,Mg0.9Ti0.06Zr0.04Ni的分泌物能力比MgNi合金的高是91.74%并且37.96%比Mg0.9Ti0.1Ni的高合金。为电极能力腐烂的主要原因是Mg的形成(哦)2(Mg腐蚀的产品)在合金的表面。potentiodynamic极化结果显示做的Ti和Zr在一个碱的答案改进耐蚀。电气化学的阻抗光谱学(EIS)结果建议做的Ti和Zr的那合适的数量显著地改进电气化学的催化活动。
简介:ByaddingmixtureofZrO2andcarbon,aZr-enhancedcompositecoatingwasproducedontoanAISI1045substratebylasercladding.Themicrostructureandphaseformation,microhardnessandwearresistanceofthecompositecoatingwerestudied.Theexperimentalresultsindicatethatthecompositecoatingwithmetallurgicalbondingtosubstrateconsistsof7-Ni,massiveceramicparticlesofZrC,NiZra,NiTZr〉(Fe,Ni)23C6andF%C.Theinsitu-synthesizedZrCparticlesareuniformlydispersedincompositecoating,whichrefinesthemicrostructureofcompositecoating.WithdifferentZrO2andcarbonaddi-tions,thepropertiesareimproveddifferently.Finally,thefineinsituZrCparticlesimprovethemicrohardnessofcompositecoatingtoHVo.2650,whichisnearly2.7timesthatofNi25coating.Also,thecompositecoatinghasanadvantageinwearresistance;itoffersbetterwearresis-tancewhenmoremixtureofZrO2andcarbonwasaddedinnickelalloys.
简介:Zr-Incorporatedmesoporoustitaniamaterialswerepreparedvianonsurfactanttemplatedsol-gelprocessofzirconium(IV)butoxide(ZBT)andtitanium(IV)butoxide(TBT)inthepresenceofureamoleculesastemplateorporeformingagent.TheeffcetsoftemplatecontentsontheporeparametersofthematerialssynthesizedwithfixedZrincorporationcontentswereinvestigatedbymitrogenadsorption-desrptionmeasurements,powderX-raydiffraction(XRD)studyandtransmissionelectronmicroscopy(TEM).ThechangesoftemplatecontentsplaysignificantrolesontheporeparametersatlowincorporsationcontentofZr.Theporediametersdisplayaclearincreasetendencywiththeincreaseoftemplatecontents.WhenhighZrincorporationcontentisused,thetemplatecontentshavelesseffectontheporediametersthatalmostkeepunchangedwiththeincreaseoftemplatecontents.AllthematerialspossesstypeIVisothermswithH2hysteresisloopssuggestingtheformationofmesophase.ThematerialswithlowZrincorporationcontenthaveanatasestructures;however,itcannotbefoundinthematerialswithhighZrincorporationcontent.TEMimagesshowthatsomeaccumulatedinter-particulateporesandwelldistributedworm-likeporesarepresentintheZr-incorporatedmaterials.
简介:Ti44Zr32Ni22Cu2和Ti41Zr29Ni28Cu2合金被融化旋转方法准备。阶段结构被X光检查衍射分析,并且融化旋转合金的电气化学的表演被调查。结果显示Ti44Zr32Ni22Cu2合金由icosahedralquasicrystals和非结晶的阶段组成,并且Ti41Zr29Ni28Cu2合金包括了icosahedralquasicrystals,非结晶,并且洗阶段。最大的分泌物能力分别地为Ti41Zr29Ni28Cu2合金是为Ti44Zr32Ni22Cu2合金和181mAh/g的141mAh/g。Ti41Zr29Ni28Cu2合金也显示出更好高率的dischargeability和骑车的稳定性。更好电气化学的性质应该被归功于到Ni的高内容,它对电气化学的运动性质有益并且在Ti41Zr29Ni28Cu2合金使合金更抵抗到氧化,以及到洗阶段,它能作为电镀物品催化剂和微水流的收集者工作。