学科分类
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45 个结果
  • 简介:TheeffectofAl-3Ti-0.2C-5Sr(wt%)grainrefinerontherefiningperformanceandmodificationofA356alloywasinvestigatedusingopticalmicroscope(OM).ThemorphologyandcrystalstructureofternaryAl-Ti-SrphasesinAl-3Ti-0.2C-5Srrefinerwereanalyzedbyscanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM).TheresultsshowthattheternaryAl-TiSrphasesinAl-3Ti-0.2C-5SrrefinercanpromotethegrainrefiningefficiencyofA356alloy.TheternaryAl-Ti-Srphasesco-existintwomorphologies,i.e.,blocky-likephaseandsurround-likephase,besides,whichbothhavethesamechemicalcompositionofAl_(34)Ti_3Sr.ThecrystalstructureofAl_(34)Ti_3Srisface-centeredcubic,andthelatticeparameterisdeterminedtobeabout1.52nm.

  • 标签: A356铝合金 透射电子显微镜 细化效果 三元 扫描电子显微镜分析 A356合金
  • 简介:Al-5Ti-0.5C-8Sr(集体部分,%)主人合金用一个melt反应方法被准备。微观结构和主人合金的合成过程被光显微镜学,X光检查衍射,扫描电子显微镜学和X光检查调查精力散的光谱。结果证明主人合金由组成一(艾尔),TiAl3,TiC,Al4Sr和Al-Ti-Sr分阶段执行。主人合金的合成机制如下:TiAl3通过在K2TiF6和艾尔之间的反应被形成在基础材料的部分融化层融化在850个C粒子与同类地分布式的加强在超声的行动和一张契约下面被变成液体filler在团结以后被获得。体积部分原文如此,在契约的粒子能被改变以铜锌金焊接的温度改变。最大值原文如此,契约材料的粒子体积部分在brazi到达了37%?

  • 标签: 中间合金 合成过程 微观结构 机制 TIAL3 X射线衍射仪
  • 简介:FluorescenceandcofluorescencepropertiesofTb(Ⅲ)solidcomplexeswerestudiedusingpyromelliticacid(PMA)asligandandfluorescenceinertionsasdopingelements.Thecofluorescenceenhancement,aresultofligandsensitizedfluorescence,wasobservedinTb(Ⅲ)solidcomplexesdopedwithfluorescentinertionsLa(Ⅲ),Gd(Ⅲ),Ca(Ⅲ),andSr(Ⅲ).Theeffectofthetypeandcontentofdopingelementsonfluorescenceenhancementwasstudied,andoptimumconditionsweredetermined.TheresultsshowthatGd(La,Ca,Sr)hasclearcofluorescenceeffectinsolidcomplexTb-M-PMAsystem,andinpresentwork,rareearthcomplexfluorescentpowderthatemitsbrightgreenfluorescenceatultravioletexcitationwasobtained,whichhadpotentialapplicationasfluorescentanti-counterfeitink.

  • 标签: 荧光增强 转光特性 铽配合物 均苯四酸 配位体 搀杂剂
  • 简介:TheprocesstoobtainhighT(110K)phasequickly,themicrostructureandpropertiesofAg-sheathedBi(Pb)-Sr-Ca-Cu-Osuperconductortapeshavebeenstudied.ItwasfoundthattheformationtimeofthehighTcphasewasgreatlyshortenedbytheadditionofmoreCaandCutothenominalcompositionofBi(Pb):Sr:Ca:Cu=2:2:2:3andtheadoptionofappropriatesinteringtemperatureandcoolingrate.SuperconductorpowderwithpredominanthighT,phasewaspreparedaftera840C/50htreatment.TheJoftheAg-sheathedtapesandthemagneticfielddependenceofJwereobviouslyimprovedbyrepeatedlypres-singandsintering.Themaximumtransportcurrentdensityat77Kinazeromagneticfieldwas12,200A/cm2.ThemagneticdependenceofJwassummarizedasfollows:6.450A/cm2(B⊥1.B∥S.0.1T)1,810A/cm2(B⊥1.B∥S,1T),390A/cm2(B⊥1.B∥S,2T)(B:magneticfield.1:electriccurrent.S:surfaceoftapes).TheimprovementofJwasattributedtotheformationoftheplate-likestructurewithhomogeneouscompositiondistributionandthestrongc-axistexture.

  • 标签: SUPERCONDUCTOR Ag-sheathed tape High T_ephase Critical
  • 简介:Theobjectiveofthisstudyistoinvestigatetheinfluenceofaddingtinyamountofmixedrareearth(La,Ce)andSrtoAl-20Cu-5Si-2Nifillermetal,byanalyzingthemicrostructure,wettabilityandmechanicalpropertiesofbrazedjoints.Theresultsshowthawiththeadditionofmixedrareearth(La,Ce)intoAl-20Cu-5Si-2Nialloy,theα-AlsolidsolutionaswellasCuAl_2(Ni)intermetalliccompoundphasesignificantlyreduced,whilemoreAl-SieutecticphaseandAl-Si-Cuternaryeutecticphasewereproduced.Andasmixedrareearth(La,Ce)addedin,thewettabilityofAl-20Cu-5Si-2Nifillermetaldecreased,whiletheshearstrengthofthebrazedjointsincreased.TheadditionofMinorSrmodificatedAl-20Cu-5Si-2Nifillermetal,furtherreducedtheCuAl_2(Ni)intermetalliccompoundphase,whichwaspartiallyreplacedAl-Si-Cuternaryeutecticphase.Asaresult,thetensilestrengthaswellasthewettabilityofthefillermetalwasimproved.

  • 标签: 混合稀土 钎焊接头 微观组织 钎料 金属间化合物相 填充金属
  • 简介:微米大小的Sr2(P2O7):Ce,Tb绿黄磷被与它的先锋在不同温度被退火准备综合了由一同沉淀(NH4)在周围的温度的2HPO4。黄磷的阶段结构,谷物尺寸,表面形态学,和光性质被X光检查衍射调查,扫描电子显微镜,传播电子显微镜,和荧光光谱。先锋的产品在1,100点退火了的结果表演??‰浮???匠??伲?????畅??

  • 标签: 绿色荧光体 共沉淀法 磷酸 扫描电子显微镜 透射电子显微镜
  • 简介:ThepermeabilityandstabilityofSm_(0.7)Sr_(0.3)CoO_(3-δ)(SSCO)regardingthespecialrequirementsforcarboncaptureandstorage(CCS)applicationwereinvestigated.PureCO_wasusedasthesweepgasat900°C,leadingtothattheoxygenpermeationfluxdecreasesbyabout34%.SeveralcyclesofchangingthesweepgasbetweenheliumandCO_2indicatethegoodreversibilityofthisdegradation.BothcarbonateformationandadsorptionofCO_2onthemembranesurfaceareresponsibleforthedegradationofthemembraneperformance.ThebetterCO_2resistanceresultsfromthesubstitutionofSmforSrduetothehigheracidityofSm_2O_3(1.278)thanthatofSrO(0.978)andadiscontinuouslayerofcarbonate.

  • 标签:
  • 简介:结构和绝缘的性质(Pb,Sr)有不同Pb和Sr内容的Nb2O6-NaNbO3-SiO2眼镜陶艺被调查。没有Sr替换的眼镜陶艺的XRD模式与Sr替换与那不同,它在后者显示斜方晶的阶段的存在。,TEM明亮的地观察与Sr为样品显示出nanosized微观结构,与分开的使结晶的乐队一起的典型最容易溶解的微观结构在玻璃矩阵被发现。当到Pb的Sr的臼齿的比率是4时,样品的绝缘的性质测量显示绝缘的常数,绝缘的损失,DC地和绝缘的常数的温度依赖的明显的改进?6。

  • 标签: SIO2玻璃 陶瓷复合材料 纳米微结构 介电性能 PB SR
  • 简介:La-dopedSr-hexaferrite(Sr_(1-x)La_xFe_(12)O_(19))(x=0.05,0.10,0.15,0.20)nanopowderswithparticlesizerangingfrom80to110nmweresuccessfullysynthesizedbysol-gelauto-combustion.Thephaseformationtemperatureincreases,whiletheparticlesizedecreasesastheLadopingcontentgoesup.ThepartialsubstitutionofSr~(2+)byLa~(3+)resultsinthesuppressioneffectsonthegrowth-upofthecrystallitesandtheenhancementoftheelectronhoppingbetweenFe~(3+)withdifferentvalences,whichleadstotheimprovementinthedielectriclossandmagneticloss.Therefore,boththemicrowaveabsorbingabilitiesandabsorbingfrequencyrangesaretunedbyLa-doping.ThesynthesizedSr-hexaferritenanopowderswithdopingelementcontentof0.10demonstratethefinebroadmicrowaveabsorbingproperties.

  • 标签: 溶胶-凝胶自燃烧法 微波吸收性能 LA掺杂 锶铁氧体 纳米粉体 合成
  • 简介:PolycrystallinesamplesofLa12x(Sr12yAgy)xMnO3(y=0.0,0.2,0.4,0.6,1.0)werepreparedbythesolid-statereactionmethod.ThetemperaturestabilityofmagnetoresistanceandmagnetoresistanceenhancementinLa1-x(Sr1-yAgy)xMnO3systemwithbothunivalentandbivalentelementsdopedatAsiteandwithunchangedvalueofMn3+/Mn4+ratiowereexploredthroughthemeasurementsofX-raydiffractionpatterns,magnetiza-tion-temperature(M-T)curves,resistivity-temperature(q-T)curvesandmagnetoresistance-temperature(MR-T)curves.Theresultsareasfollows:therearetwopeaksintheq-TcurvesofthesampleswithAgdoping,oneiscausedbyresistancechangeduringtheparamagnetism-ferromagnetismtransition,andtheotherisfromboundary-dependentscatteringofconductionelectronsontheboundariesofgrains.ThepeakvalueofMRincreaseswithincreasingAgdopingcontent,anditincreasesfrom8.2%fory=0.2to29.6%fory=1.0underthemagneticfieldofB=0.8T;MRremainsaconstantof12%inthetemperaturerangeof218-168Kforthesamplewithy=1.0,andthetemperaturestabilityofMRisinfavorofthepracticalapplicationofMR.

  • 标签: 温度稳定性 MR 系统 温度曲线 磁阻 AG掺杂
  • 简介:近几年随着我国工业自动化程度的大幅提高.全国各地的锻造企业对锻造操作机的要求也变得越来越高。锻造操作机是锻件精确制造的基本装备之一,与自由锻造压机配合实现锻造作业.可极大提高锻造生产效率和锻件制造质量.降低制造成本。锻造用操作机和锻造用装取料机在提高锻造效率、优化锻造工艺方面的优势已经突显出来,在锻造安全作业中起到越来越重要的作用。锻造用机器人、操作机是锻造自动化的重要辅助设备.对节省人力,提高生产效率起到不可代替的作用。

  • 标签: 锻造操作机 制造成本 生产效率 安全作业 自动化程度 锻造自动化
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  • 标签: 制造系列丛书 模具制造 系列丛书邮购目录
  • 简介:本文通过介绍TF系列预合金粉末的基本性能和应用情况,讨论预合金粉末的形貌、组成、杂质含量等对金刚石工具制备质量的影响,揭示了预合金粉末的发展方向。

  • 标签: 预合金粉末 性能 应用
  • 简介:西安,古称长安.与雅典、罗马和开罗并称为世界四大文明古都.“西罗马,东长安”是其世界历史地位的写照。这个举世闻名的古都,曾经承载了历史上十三个朝代。因此,俗有”二十年中国看深圳,五千年中国看西安”之说。

  • 标签: 西安 企业 宝鸡 世界历史 长安 罗马