学科分类
/ 3
50 个结果
  • 简介:CurieTemperatureofAmorphousFeSiBandFeWSiBAloysWangLingling,ZhaoLihua,HuWangyu(王玲玲)(赵立华)(胡望宇))DepartmentofPhysics,HunanUn...

  • 标签: CURIE TEMPERATURE FeSiB and FeWSiB ALLOYS
  • 简介:ArapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cr(massfractionin%)alloywaspreparedbymeltspinning.Asquenchedandas-annealedmicrostructureswerestudiedbyX-raydiffractometry(XRD),transmissionelectronmicroscopy(TEM),high-resolutiontransmissionelectronmicroscopy(HREM)andenergydispersivespectrum(EDS)analysis.Themicrohardnessofthealloyatdifferentannealingtemperatureswasmeasured.TheresultsobtainedindicatethatthemicrohardnessoftherapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cralloydoesnotvarywithdifferentannealingtemperatures.Theas-quenchedmicrostructureofthealloyincludestwokindsofdispersedprimaryphases:Al3TiandAl13(Cr,Fe)2.Afterannealingat400℃for10h,thestablephaseAl13Fe4appearsinthemicrostructure.

  • 标签: Al-Ti-Fe-Cr合金 微结构 热稳定性
  • 简介:X-raydiffraction(XRD)anddifferentialscanningcalorimetry(DSC)wereusedtoinvestigatethecrystallizationprocessofamorphousAl90TMxCe10-x(atomfractionin%;TM=FeorNi;x=3,5)alloys.AgingeffectswereexaminedbyX-raydiffraction.ThestructurecorrespondingtotheprepeakfortheamorphousAl90Fe5Ce5alloyismorestablethantheamorphousmatrix,butitisnotstableforamorphousAl90Ni5Ce5alloyduringthefirstcrystallizationstageandevendecomposesatroomtemperature.AlthoughbothAl-NiandAl-Fehavestrongchemicalbonding,thecrystallizationonsettemperatureofamorphousAl-Fe-CealloysismuchhigherthanthatofamorphousAl-Ni-Cealloys,whichislikelycausedbythedifferentstabilityofthestructurecorrespondingtotheprepeak.ThecrystallizationonsettemperatureincreasesasCe/NiratioincreasesinamorphousAl90NixCe10-xalloys,whereasitdecreasesasCe/FeratioincreasesinamorphousAl90FexCe10-xalloys.AbetteratomicpackingproducesasCecontentincreasesbecauseofthesizemismatchinAlNi-CesystemsandasFecontentincreasesbecauseoftheincreasingFecentralstructuralunits.

  • 标签: 非晶形合金 Al90TMxCe10-x合金 稳定性
  • 简介:InordertoimprovetheelectrochemicalcyclestabilityofLa-Mg-Nisystem(PuNi3-type)hydrogenstoragealloy,NiinthealloyswaspartiallysubstitutedbyM(M=Cu,Al,Mn).AnewLa-Mg-NisystemelectrodealloysLa0.7Mg0.3Ni2.55-xCo0.45Mx(M=Cu,Al,Mn;x=0,0.1)werepreparedbycastingandrapidquenching.Theeffectsofelementsubstitutionandrapidquenchingonthemicrostructuresandelectrochemicalperformancesofthealloyswereinvestigated.TheresultsbyXRD,SEMandTEMshowthatthealloyshaveamultiphasestructure,includingthe(La,Mg)Ni3phase,theLaNi5phaseandtheLaNi2phase.Therapidquenchingandelementsubstitutionhaveanimperceptibleinfluenceonthephasecompositionsofthealloys,butbothchangethephaseabundanceofthealloys.Therapidquenchingsignificantlyimprovesthecompositionhomogeneityofthealloysandmarkedlydecreasesthegrainsizeofthealloys.TheCusubstitutionpromotestheformationofanamorphousphaseintheas-quenchedalloy,andareversalresultbytheAlsubstitution.Theelectrochemicalmeasurementindicatesthattheelementsubstitutiondecreasesthedischargecapacityofthealloys,whereasitobviouslyimprovesthecyclestabilityofthealloys.ThepositiveinfluenceofelementsubstitutiononthecyclelifeofthealloysisinsequenceAl>Cu>Mn,andnegativeinfluenceonthedischargecapacityisinsequenceAl>Mn>Cu.Therapidquenchingsignificantlyenhancesthecyclestabilityofthealloys,butitleadstoadifferentextentdecreaseofthedischargecapacityofthealloys.

  • 标签: element SUBSTITUTION rapid QUENCHING La-Mg-Ni system
  • 简介:InfluenceofImpurityGermaniumonPropertyofCZ-SiZhangWeilian;LiuCaichi;WangZhijunandJiZhijiang(张维连)(刘彩池)(王志军)(冀志江)(MaterialResea...

  • 标签: CZ-SI Ge-doping MECHANICAL PROPERTY
  • 简介:FractureCharacteristicsofSiC(p)/AlCompositesGuHongwei;CaoLi;YuanGuansen;LiuAnsheng;WuZiqinandChenLanfeng(古宏伟),(曹利),(袁冠森),(刘安生...

  • 标签: SIC AL COMPOSITE
  • 简介:Wehaveobservedsomekindsofdefectsinunseededrapidzone-melting-recrystallized(RZMR)SifilmsformedwithaRF-inducedgraphitestripheatersystem,usingcross-sectionspecimenelectronmicroscope.Theobserveddefectsaresubgrainboundaries(SGB),dislocationsandmicrotwins.ThemostcommonlyobserveddefectsareSGBwhichformedasaresultofsomeorientationdifferencesbetweenadjacentgrainsduringtheirrapidself-nucleationgrowth.MixedtypeSGBwerefrequentlyobserved,althoughsomepuretiltortwistSGBexistedalsointheSifilms.Therotationangularcomponentaroundtheaxisparalleltoscanningdirectionismuchlargerthanthataroundotheraxes.SGBconsistprimarilyofarraysofdislocationandhavecrystallographicangulardeviationsofonedegreeorless.DuringSifilmcooling,dislocationsandmicrotwinswereformedduetonon-uniformthermalstress.ThecrystallographiccharactersofthedislocationsinSifilmsarethesameasthoseincommonbulkSisinglecrystals.TheirBurgersvectorsareb=a/2<110>.Somedis-locationsrunacrosstheSifilm,andtheamorphousSiO2layersonandunderneaththeSifilmcaneffectivelyblockthedislocationsandpreventthemfromenteringthelayers.MicrotwinswereobservedintheSifilmssometimes,thetwinningplanesbeing{111}.

  • 标签: SILICON on insulator(SOI) Zone-melt-recrystallization(ZMR) SILICON film
  • 简介:InordertocontrolthesizeanddistributionofthehighconductiveFe2PinLiFePO4/Fe2Pcomposite,twodifferentcoolingrates(Fast:15℃·min-1,Slow:2℃·min-1)wereemployedaftermechanicalalloying.Thedischargecapacityofthefastcooledwas83mAh·g-1andtheslowcooled121mAh·g-1.TheparticlesizeofthesynthesizedpowderwasexaminedbytransmissionelectronmicroscopyanddistributionofFe2Pwascharacterizedusingscanningelectronmicroscopy(SEM).Inaddition,two-stepheattreatmentwascarriedoutforbetterdistributionofFe2P.X-raydiffraction(XRD)andRietveldrefinementrevealthatLiFePO4/Fe2Pcompositeconsistsof95.77%LiFePO4and4.33%ofFe2P.

  • 标签: LiFePO4/Fe2P COMPOSITE mechanical ALLOYING HEAT treatment
  • 简介:阶段形成,居里温度,和NaZn_(13)类型LaFe_(11.7)Si_(1.3)的磁性的熵变化上的碳的影响被调查。七carbon-containingalloys,有x=的LaFe_(11.7)Si_(1.3)C_x分别地,0,0.03,0.06,0.10,0.20,0.30,和0.50为这调查作好准备。试验性的结果证明在LaFe_(11.7)Si_(1.3)的碳的小数量的增加为NaZn_(13)类型结构ofLaFe_(11.7)的形成是有利的Si_(1.3)C_x。晶格常数与C增加增加,因为C同样空隙的原子的介绍,x在合金增加。当x从0~0.5增加,居里温度ofLaFe_(11.7)Si_(1.3)C_x从194K增加到225K。因为他们的一阶的结构/磁性的转变,大磁性的熵变化在这些包含碳的合金LaFe_(11.7)Si_(1.3)C_x被观察。27.5J·kg~的最大的磁性的熵变化(在为0-1.56T磁场变化的202K的-1)·K~(-1)与x=在合金被观察0.06。相应于LaFe_(11.7)的材料的变化,和低成本Si_(1.3)C_x使它成为的低磁场的大磁性熵的变化在对应温度范围要用作磁性的refrigerants的一个有希望的候选人。

  • 标签: LaFe11.7Si1.3 碳加合物 磁热效应 合金 性质
  • 简介:StudyonGdAlDySystemMagneticRefrigerationMaterialsChangXiumin,YanJunlian(常秀敏)(闫俊联)BeijingGeneralResearchInstituteforNonferr...

  • 标签: SINTERING MAGNETIC REFRIGERATION materials CURIE temperature
  • 简介:TheDCcharacteristicsofSiGeHBTirradiatedatdifferentelectrondosehavebeenstudiedinacomparisonwiththoseofSiBJT.Generally,IbandIb-Ib0increase,Ic,Ic-Ic0andits+/-transitionVbeaswellasDCcurrentgainβdecreaseswithincreasingdose;increaseofIb-Ib0withincreasingdoseforSiBJTismuchlargerthanthatforSiGeHBT;βincreaseswithVbeorIb,butdecreasesatIb<0.25mAwithIb,andcongregatesathigherdose;andadamagefactord(β)ismuchlessatthesamedoseforSiGeHBTthanforSiBJT.SiGeHBThasmuchbetteranti-radiationperformancethanSiBJT.SomeanomalousphenomenaforincreaseofIc,Ic-Ic0,Ib-Ib0andβatlowdosehavebeenfound.Someelectrontrapshavebeenmeasured.Themechanismofchangesofcharacteristicsisdiscussed.

  • 标签: 微波器件 砷化镓 硅-锗 HBT 直流电 半导体器件
  • 简介:MicrostructureandtextureofTi-Nb-Sibasedalloys,preparedbywaterquenchingfromβ-phasefield,coldrollingandrecrystallizationheattreatmentfollowedbywaterquenching,wereinvestigatedintermsofopticalmicrostructureandanalysisofX-raypolefigureresult.Inas-quenchedsample,relativelyrandomdistributionofpolefigurewasdetectedwithoutshowingaspecifictexturecomponent.Inas-coldrolledsample,however,itisfoundwell-developedseveraltexturecomponentsconsistingofrotatedcube,α-fiberandγ-fibertexturecomponentswhicharefrequentlyobservedinbcc-structuredmetalsandalloyswerefound.Therefore,texturecomponentsdevelopedinthepresentalloysarecloselyrelatedtothedeformationofβ-phaseeventhoughsmallamountofα″phaseco-existinthemicrostructure.Inrecrystallizedsample,α-fibertexturecomponentisweaklydetectedwhiletheothertexturecomponents,rotatedcubeandγ-fibercomponents,appearstoberelativelyunchanged.Noadditionaltexturecomponentsweredetectedbesidesthosetexturecomponentsobservedinthecoldrolledsamples.

  • 标签: Ti-Nb-Si BASED ALLOYS MICROSTRUCTURE TEXTURE
  • 简介:ThesolidsolubilityofCe、La、SmandNdinFeorNiatvarioustemperaturewasdeterminedbymeansofadiffusion-couplemethodwiththeaidofanelectronprobemicroanalyzer.Twomethods,namelyareamethodandwholerangemethod,wereproposedfordataprocessinginthepresentpaper.Theprincipleandre-latedproblemsintheexperimentaldeterminationofthesolidsolubilityofrare-earthelementsinFeorNibyuseoftheabovementionedmethodswerealsodiscussed.

  • 标签: Solid SOLUBILITY RARE earths FE NI
  • 简介:ThemicrostructuresandVickershardnessatroomtemperatureofarc-meltingprocessedintermetallicsofMo5Si3-MoSi2hypoeutecticalloyandhypereutecticalloyannealedat1200℃fordifferenttimewereinvestigated.LamellarstructureconsistedofMo5Si3(D8m)phaseandMoSi2(C11b)phasewasobservedinallthealloys.ForMo5Si3-MoSi2hypoeutecticalloy,thelamellarstructurewasfoundonlyafterannealinganddevelopedwellwithfinespacingontheorderofhundrednanometersafterannealingat1200℃for48h.Butwhentheannealingtimewasupto96h,thewell-developedlamellarstructurewasdestroyed.ForMo5Si3-MoSi2hypereutecticalloy,thelamellarstructurewasfoundbothbeforeandafterannealing.Howeverthevolumefractionandspacingofthelamellarstructuredidnotchangesignificantlybeforeandafterannealing.Theeffectsoftheformation,developmentanddestructionoflamellarstructureonVickershardnessofalloyswerealsoinvestigated.WhenMo5Si3-MoSi2hypoeutecticalloyannealedat1200℃for48h,theVickershardnesswasimprovedabout19%comparedwiththatwithoutannealingandformationoflamellarstructure.ThehighestVickershardnessofMo5Si3-MoSi2hypereutecticwasincreasingabout18%whenannealingat1200℃for48h.

  • 标签: 室温 钼-硅系统 层状结构 显微结构 维氏硬度 退火
  • 简介:ThehydrogenstoragepropertiesofTi1.2Fe+xCa(x=1%,3%and5%inmassfraction)alloyswasinvestigated.ResultsshowthatthemodifiedalloyscanbeactivatedwithoutanythermaltreatmentatroomtemperatureduetotheadditionofCaandexcessTiinthealloys.HydrogenstoragepropertiesofthesemodifiedalloysvarywithCaamountandreactiontemperature.Inaddition,theinfluencemechanismoftheadditionofCaandexcessiveTiontheactivationbehaviorandhydrogenstoragecapacityofthealloyswasdiscussed.

  • 标签:
  • 简介:本文探讨了合金元素和退火温度对Cu-0.1Ag-xP-yMg和Cu-xSn-yTe合金(所有成分均为质量分数/%)的导热率和软化行为的影响.尽管Cu-0.1Ag-xP-yMg合金中P和Mg的含量较高,但该合金的导电率和软化温度仍然高于Cu-0.1Ag-0.031P合金.Cu-0.032Sn-0.023Te合金的导电率和软化温度与Cu-0.040Sn合金处在同一水平.Cu-0.032Sn-0.023Te合金的导电率和软化温度与目前用于连铸型材料的Cu-0.1Ag-0.013P合金相当.

  • 标签: 元素铜基 合金元素 合金导热
  • 简介:Thecorrosionbehaviorandanti-corrosionmechanismoftheZn-Ni-Al2O3compositecoatingwereinvestigatedbySEM,EDSandXPS.TheresultsindicatethatthecorrosiontypeoftheZn-Ni-Al2O3coatingsinneutral5wt.%NaClsolutionisuniformcorrosion.ThepresenceofcompactanduniformlydispersednanoaluminaparticlessubstantiallyinhibitsthecorrosionofZn-Ni-Al2O3compositecoatings.Intheinitialcorrosionstage,thecorrosiveproductsofZn-NimatrixformacompactZnCl2·4Zn(OH)2layer.Withthedevelopmentofcorrosion,somenanoaluminaparticlesareembeddedandformaNienrichmentlayer.InNienrichmentlayer,NipresentsasNiandNiO.

  • 标签:
  • 简介:ThestoredenergyandtheenergyreleaseduringSPD(superplasticdeformation)ofaZn-5Alalloywerestudied.Thealloyafterrollingprocessgainsmorestoredenergy,andtheas-rolledspecimencanobtainmaximumelongationandminimumflowstresswithouthotholdingtreatmentbeforeSPD.ExperimentalresultsshowthatstoredenergyreleaseprocessisalongwithSPDprocessandisalsoanimpetustoSPD.Theas-rolledZn-5Alalloyhas48J/molstoredenergywhichwasmeasuredwithDSC(differentialscanningcalorimeter)andconformswelltothecalculatedvalue.Theas-rolledZn-5AlalloyafterSPDwithanelongationof2500%releases112J/molstoredenergy.Analysisshowsthatthestrainrateisindirectratiototherateofstoredenergyrelease.

  • 标签: Zn-5Al低共熔合金 超塑性变形 储能分析
  • 简介:Thestructure,CurietemperatureandmagnetostrictionofPr0.15Tb0.30Dy0.55Fe1.85Cx(x=0-0.1)compoundswereinvestigatedbyX-raydiffraction,avibratingsamplemagnetometerandastandardstraintechnique.AllthesamplesshowentirelyMgCu2-typeLavesphasestructure.ThelatticeparameterandCurietemperatureincreasewithCcontentincreasing.Themagnetostrictionathighmagneticfieldshowsmaximumvalueatx=0.05.

  • 标签: MAGNETOSTRICTION Pr0.15Tb0.3Dy0.55Fe1.85 Laves PHASE