学科分类
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500 个结果
  • 简介:利用高频辅助激光熔覆技术在镍基合金上制备Al2O3-13%TiO2(质量分数)陶瓷涂层。采用SEM、XRD和EDS等方法分析陶瓷涂层的微观结构和陶瓷层与粘结层之间的结合界面。结果表明:陶瓷层出现了完全熔化区和液相烧结区双层结构,其中,完全熔化区颗粒充分烧结长大,而液相烧结区则出现了三维网状结构,该三维网状结构由熔化的TiO2相包裹Al2O3颗粒形成。通过激光熔覆作用下的粉末熔化和扁平化行为解释双层结构形成机理。同时,在陶瓷层与粘结层的结合界面上发现具有尖晶石结构的NiAl2O4和针状结构的Cr2O3,证明在激光熔覆过程中发生的化学反应可以有效增加陶瓷层与粘结层的结合强度。

  • 标签: 陶瓷涂层 镍基合金 激光熔覆 Al2O3-TiO2 高频辅助
  • 简介:采用碱熔处理样品,酸化后,移取部分溶液稀释后引入ICP测定ZrO2TiO2、Fe2O3含量,剩余溶液用强碱分离钛、铁、锰等干扰元素后,EDTA—CuSO4法返滴定Al2O3,终点明显,检测重现性好;

  • 标签: FE2O3 AL2O3 ZRO2 TIO2 测定方法 质砖
  • 简介:A60%Fe/Al2O3catalystwaspreparedbytheco-precipitationmethod.ItwasreducedbyH2toproducemetallicFe,whichwasthensulfidedbyCS2toFe0.96SandFe3S4orphosphidedbytriphenylphosphine(PPh3)inliquidphasestoFe2PandFeP.Itwasfoundthattheironsulfides(Fe0.96SandFe3S4)exhibitedthelowactivityforthehydrodesulfurization(HDS)reactions.TheHDSactivitywasalsolowontheFe(metal)/Al2O3andFe2P/Al2O3catalystssincetheywereconvertedintoFe0.96SandFe3S4duringtheHDSreactions.Incontrast,theFeP/Al2O3wasfoundtobestableandactivefortheHDSreactions.Inparticular,FeP/Al2O3possessedsignificantlysmallerFePparticlesthanFeP/C,leadingtothesignificanthigherHDSactivityofFeP/Al2O3thanFeP/C.

  • 标签: Fe2P/Al2O3 CATALYST FeP/Al2O3 CATALYST Liquid phase
  • 简介:本文利用中压(.OMPa)固定床流动反应装置研究了不同Co含量对MoO/TiO─Al催化剂加氢脱硫性能的影响.结果表明,少量Co助剂的引入可显著提高催化剂的加氢脱硫活性,但对加氢活性影响较小.Co/Co+Mo原子比在0.25~0.45范围内催化活性最高.

  • 标签: 加氢脱硫 CoMo/TiO2─Al2O3 加氢 Co/Co+Mo原子比
  • 简介:ThecorrelationbetweenphasestructuresandsurfaceacidityofAl2O3supportscalcinedatdifferenttemperaturesandthecatalyticperformanceofNi/Al2O3catalystsintheproductionofsyntheticnaturalgas(SNG)viaCOmethanationwassystematicallyinvestigated.Aseriesof10wt%NiO/Al2O3catalystswerepreparedbytheconventionalimpregnationmethod,andthephasestructuresandsurfaceacidityofAl2O3supportswereadjustedbycalciningthecommercialγ-Al2O3atdifferenttemperatures(600–1200C).COmethanationreactionwascarriedoutinthetemperaturerangeof300–600Catdifferentweighthourlyspacevelocities(WHSV=30000and120000mL·g-1h-1)andpressures(0.1and3.0MPa).ItwasfoundthathighcalcinationtemperaturenotonlyledtothegrowthinNiparticlesize,butalsoweakenedtheinteractionbetweenNinanoparticlesandAl2O3supportsduetotherapiddecreaseofthespecificsurfaceareaandacidityofAl2O3supports.Interestingly,NicatalystssupportedonAl2O3calcinedat1200C(Ni/Al2O3-1200)exhibitedthebestcatalyticactivityforCOmethanationunderdifferentreactionconditions.LifetimereactiontestsalsoindicatedthatNi/Al2O3-1200wasthemostactiveandstablecatalystcomparedwiththeotherthreecatalysts,whosesupportswerecalcinedatlowertemperatures(600,800and1000C).ThesefindingswouldthereforebehelpfultodevelopNi/Al2O3methanationcatalystforSNGproduction.

  • 标签: Ni catalyst ALUMINA CO METHANATION synthetic
  • 简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.

  • 标签: ALUMINA active BRAZING INTERFACIAL reaction joint
  • 简介:钛酸铝系复合材料中钛酸铝的体积分数不同,会导致Al2TiO5/Al2O3复合材料的抗铝液浸渗性能的不同。在Al2TiO5中分别按10%、20%、40%、60%、80%、90%(体积分数)引入Al2O3进行复合。通过对渗铝试样的外观形貌、微观结构分析,进而对其铝液浸渗性能进行了分析比较,发现富钛酸铝的钛酸铝/氧化铝复合材料(妒(AL2TiO5)〉40%)抗铝液浸渗性能好;而富氧化铝的钛酸铝/氧化铝复合材料(φ(Al2TiO5)〈20%)有金属铝液沿热震产生的裂纹渗入复合材料内部,容易导致复合材料断裂失效。该研究结果对可靠应用钛酸铝系复合材料作为铝液的容器具有实际工程应用价值。

  • 标签: 钛酸铝 氧化铝 抗铝液浸渗性能 复合材料
  • 简介:TheinfluenceofcalcinationtemperatureonTiO2nanotubes’catalysisforTiO2/UV/O3wasinvestigated.TiO2nanotubes(TNTs)werepreparedviathesol-gelmethodandcalcinedat300—700℃,whichwerelabeledasTNTs-300,TNTs-400,TNTs-500,TNTs-600andTNTs-700,respectively.TNTswerecharacterizedbytransmissionelectronmicroscopy(TEM)andX-raydiffraction(XRD).ItisfoundthatTNTscalcinedat400℃showedthebestthermalstability.Whenthecalcinationtemperatureincreasedfrom400℃to700℃,thespecialstructureoftubeswasdestroyedandgraduallyconvertedintonanorodsand/orparticles.Thetransformationfromanatasetorutileoccurredat600℃,andtherutilephasewasenhancedwhenthecalcinationtemperaturewasincreasedtoover600℃.Thecalcinationtemperature’sinfluenceonTNTs’adsorptionactivityforchemicaloxygendemand(COD)andcatalyticactivityforTiO2/UV/O3wasinvestigatedinlandfillleachatesolution.Inlandfillleachatesolution,theadsorptionactivityofCODdecreasedinthereducedorderofTNTs-300,TNTs-400,TNTs-500,TNTs-600andTNTs-700.Inphotocatalyticozonation,TNTs-400showedthebestcatalyticactivitywhileTNTs-700exhibitedtheworst.Inotherthreeprocesses,theCODremovalofTNTs-300/UV/O3washigherthanthoseofTNTs-500/UV/O3andTNTs-600/UV/O3inthefirst20min,andthenbecameclosetothoseofthelattertwointhefollowing40min.ComparedwithTNTs-300andTNTs-400,TNTs-600hadthebestanti-foulingactivity,whileTNTs-500andTNTs-700hadloweranti-foulingactivitythantheformerthree.Inphotocatalyticozonation,thecalcinationtemperatureof400℃wasappropriatewhenTNTswereobtainedatthesynthesistemperatureof105℃.

  • 标签: TIO2纳米管 垃圾填埋场 焙烧温度 渗滤液 催化
  • 简介:本文在同一条件下分别测试了硫化态的催化剂CoMo/(TiO-Al)及氨化态的MoN催化剂的加氢脱硫和加氢脱氮性能,结果表明,对于噻吩的加氢脱硫反应,硫化态催化剂CoMo/(TiO-Al)在催化活性及稳定性方面都优于MoN,而MoN在吡啶的加氢脱氮反应中显示了较大优势.

  • 标签: Mo2N CoMo/(TiO2-Al2O3) 加氢脱硫 加氢脱氮
  • 简介:本文在同一条件下分别测试了硫化态的催化剂CoMo/(TiO-Al)及氨化态的MoN催化剂的加氢脱硫和加氢脱氮性能,结果表明,对于噻吩的加氢脱硫反应,硫化态催化剂CoMo/(TiO-Al)在催化活性及稳定性方面都优于MoN,而MoN在吡啶的加氢脱氮反应中显示了较大优势.

  • 标签: Mo2N CoMo/(TiO2-Al2O3) 加氢脱硫 加氢脱氮
  • 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:HotcompressionbehaviorofTiC–Al2O3/AlcompositeswasstudiedusingtheGleeble-1500systematatemperaturerangeof300–550°Candatstrainraterangeof0.01–10.00s-1.TheassociatedstructuralchangeswerestudiedbyTEMobservations.Theresultsshowthatstressleveldecreaseswithdeformationtemperatureincreasingandstrainratedecreasing,whichcanberepresentedbyaZener–Hollomonparameterinanexponent-typeequationwithhotdeformationactivationenergyQof172.56kJ·mol-1.Dynamicrecoveryoccurseasilywhenstrainratesarelessthan10.00s-1.Dynamicrecrystallizationcanoccuratstrainrateof10.00s-1.

  • 标签: TiC–Al2O3/Al COMPOSITES HOT DEFORMATION Flow stres
  • 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