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388 个结果
  • 简介:Inthepresentpaper,novelsidewallmaterialsforaluminumreductioncellwerepreparedinairusingmagnesiaandmagnetiteasstartingmaterials.ThesinteringbehaviorsofthespecimenswereinvestigatedbymeansofX-raydiffraction(XRD)andscanningelectronmicroscope(SEM).AndcorrosiontestsinaNa_3AlF_6-AlF_3-K_3AlF_6bathwereconductedtoevaluatetheelectrolytecorrosionresistance.TheresultsshowthattheFe_3O_4phaseistransformedintoFe_2O_3athightemperatures,whichinturnreactswiththeMgOaddedtoformMgFe_2O_4spinel.AndwithincreasingtheMgOcontentfrom0to30mass%,densificationofthespecimensdecreasesmainlyduetolargervolumeexpansionresultingfromformationofmoreMgFe_2O_4.ThecorrosiontestsshowthatcorrosionlayersareproducedinalltheMgOaddedspecimens.However,forspecimenscontainingMgFe_2O_4phaseonly,Mg(Al,Fe)_2O_4compositespinellayersarealsogenerated,whichremarkablyimprovethecorrosionresistanceofthespecimens.

  • 标签: 制备 X射线衍射仪 扫描电子显微镜 腐蚀试验 耐腐蚀性 MGO含量
  • 简介:α-Fe^2O^3材料在陶瓷、催化剂、颜料、防腐、感光材料和磁性材料等方面都有着重要的应用,而且因其原料来源丰富、用途极广,因而受到格外关注。所以,均分散α-Fe^2O^3胶体粒子的制备,不仅在理论研究具有较高价值,而且在实际应用上也有重要意义。

  • 标签: α-Fe^2O^3粒子 微波法 均分散 制备 透射电镜
  • 简介:ThemechanicalpropertiesofpressurelesssinteringFe-Si3N4bondedSiCandSi3N4bondedSiCwithsamemanufactureprocesshavebeencomparedinthispaper.TheoxidizingmechanismofFe-Si3N4bondedSiCceramicmatrixcompositehasbeeninvestigatedespeciallythroughTG-DSC(thermogravimetricanalysis-differentialscanningcalorimeter)experiment.DuringoxidationprocedurethemainreactionistheoxidationofSiCandSi3N4,SiO2whichformprotectingfilmtopreventfurtheroxidizing.AndresidualironinthesamplesbecomeFe2O3andFe3O4,theoxidationkineticsat1100~1300℃ofre-Si3N4bondedSiChasbeenstudiedespecially.Theweightgainperunitareaatinitialstagechangesaccordingtobeelinerule,inthemiddleaccordingtoconic,andinthelastoxidationperiodfollowsparabolarule.

  • 标签: SIC SI3N4 耐火材料 热冲击 等温线
  • 简介:介绍了用微波辐照均相制备α-Fe2O3胶体粒子的方法。实验表明:采用微波辐照均相制备,可在较短时间内得到均匀分散的α-Fe2O3粒子,其尺寸大且产量大。

  • 标签: 微波辐照法 均相制备 Α-FE2O3 胶体粒子
  • 简介:AnO'-Sialon-Al2O3compositerefractorywaspreparedbyinsitureactionofSi3N4-ZrSiO4-Al2O3mixturewithfusedaluminaaggregates.Densification,insitureactionprocedureandmicrostructureofthematerialwereinvestigatedbymeansofX-raydiffraction,opticalandscanningelectronicmicroscopesandEDAX.

  • 标签: O′-硅铝氧氮聚合材料 氧化锆 三氧化二铝 AL2O3 SIO2 ZRO2
  • 简介:采用溶胶-凝胶法,以硝酸铁(Fe(NO33·9H2O)和钛酸丁酯(Ti(OBu)4)为原料制备出均匀透明的TiO2-Fe2O3复合异质结构光催化薄膜材料,并将其在不同温度下进行了热处理。利用原子力显微镜(AFM)、紫外-可见分光光度计对试样的表面形貌和透光率进行了表征。考察了不同组成、热处理制度和温度对材料光催化性能的影响,特别是对可见光区的光催化性能的影响,并对其光催化机理进行了探讨。结果表明:TiO2-Fe2O3复合异质结构光催化薄膜的光催化活性比纯TiO2结构薄膜有了明显提高.且向可见光波段偏移。

  • 标签: 溶胶-凝胶法 异质结构 光催化 TiO2-Fe2O3 薄膜 可见光
  • 简介:本文采用溶胶一凝胶法成功制备了Ca3Co4O9粉体。通过分析样品的显微结构与物相组成。优化了制备工艺。结果表明,溶胶一凝胶法制得的Ca3Co4O9为取向无规则的片状组织;750℃下预烧保温2h是本试验较合适的热处理条件。

  • 标签: 溶胶-凝胶 CA3CO4O9 纳米粉
  • 简介:MgO-Al2O3-Cr2O3rammingmixesmadeofdifferentrawmaterialshavedifferentmineralstructureanddifferentphysicalpropertiesthoughwiththeidenticalparticlesizedistribution,thesameamountofbinderandchemicalcomposition.Theresidualcarboncontentofthefusedmagnesia-chromematerialmadeinreducingatmosphereisveryhigh,ifthismaterialsisusedintheMgO-Al2O3-Cr2O3rammingmix,itwouldcausespallingofthefurnaceliningduringdrying-out.

  • 标签: 原材料 氧化镁 三氧化二铬 搪炉料 搪包料 三氧化二铝
  • 简介:采用Nb2O3、Y2O3复合稳定剂,制得了高韧性、高强度的四方相ZrO2陶瓷材料,发现在Y2O3-ZrO2材料中加入0.5~1molNb2O3,可使材料在保持原有抗弯强度的同时,一定程度上改善了断裂韧性和相组成。

  • 标签: Nb2O3-Y2O3-ZrO2陶瓷 制备 复合稳定剂 应力诱导相变 韧性
  • 简介:本文主要研究添加微量稀土La2O3对Li2O-Al2O3-SiO2微晶玻璃晶相组成,显微结构,抗折强度的影响,研究结果表明:添加微量La2O3有利于Li2O-Al2O3-SiO2微晶玻璃中的主晶相β-锂辉石发育成完整的柱状,板状晶体,提高了微晶玻璃的抗折强度。

  • 标签: 稀土La2O3 LI2O-AL2O3-SIO2 微晶玻璃 结构 性能 影响
  • 简介:TherearemanyprocessestoproduceCr2O3fromchrome-ores,DifferentparticlesizerangesofCr2O3powder,finepinmentgradegreenCr2O3andcoarsemetallurgygradeblackCr2O3,aremadebydifferentprocessesinChina,GreenCr2O3assuperfineandadditionandmetallurgygradeblackCr2O3usedtosynthesizeCr2O3graincanbeappliedtorefractories.ItisverydifficultforhighpurityCr2O3tosintertodensificationandTiO2additioniscontributedtodensificationofCr2O3sinteredathightemperature,Cr2O3grainswithrelativedensityof91%-95%aregainedbysinteringCr2O3withTiO2additionandelectrofusingCr2O3rawmaterials.

  • 标签: 三氧化二铬 CR2O3 原料 耐火材料
  • 简介:Themicrostructureandslagerosionfractaldimensionofreactioninterfaceofβ-Sialon-Al2O3brickusedin300MtironladleofBaosteelhavebeenstudiedbySEMandXRD.Theresultsindicatedthatβ-Sialon-Al2O3brickexhibitedexcellentslagresistance.Themainwearmechanismofβ-Sialon-Al2O3brickismainlyfromthespallingcausedbythermalmechanicalstressandattackedbyslagsecondly.

  • 标签: 耐火材料 三氧化二铝 制备 β-硅铝氧氮聚合材料 石英砖 显微结构
  • 简介:Al2O3-MgOcastableshavebeenwidelyusedforworkingliningsofsteelladleduetotheirsuperiorhotstrengthandcorrosionresistance.Inthiswork,effectsofmicrosilica,ultrafinealuminaandMgOfinesadditionsontherheologicalbehaviorofthecastableswereinvestigatedbymeansofIBBrheometerV1.0tomeasuretorque(shearstress)undervaryingshearrates.Theresultsshowthatrheologicalpropertiesofcastablesatvaryingshearratesaresignificantlyimprovedwithincreaseofmicrosilicaadditions(from1mass%to5mass%)andcorrespondingdecreaseinwateraddition;thereisonlylittlechangeinrheologicalbehaviorwithvariationofultrafinealuminaandMgOfinesadditions.Optimumultrafinealuminaandmicrosilicaadditionsarerecommendedforcastableswithgoodrheologicalbehavior.

  • 标签: 超细氧化铝 流变行为 浇注料 氧化镁 水泥 剪切速率
  • 简介:TheinfluencesoffourkindsofadditivesaddedintothematrixofMgO-Al2O3unbunedproductswereinvestigated,TheresultsshowthatsampleswithproperMgO/Al2O3rationandproperadditionofCr2O3(2%-4%)havegoodthermalshockresistanceandslagcorrosionresistanceaswell,XRDandSEMdeterminationresultsindicatethatakindofcompoundspinel(Mg,Al,Cr)O4wasformedandthemicrostuctureofthesamplesaredenser.

  • 标签: 添加剂 性质 氧化镁 三氧化二铝 三氧化二钴 耐火材料