简介:MgO-Al2O3-Cr2O3rammingmixesmadeofdifferentrawmaterialshavedifferentmineralstructureanddifferentphysicalpropertiesthoughwiththeidenticalparticlesizedistribution,thesameamountofbinderandchemicalcomposition.Theresidualcarboncontentofthefusedmagnesia-chromematerialmadeinreducingatmosphereisveryhigh,ifthismaterialsisusedintheMgO-Al2O3-Cr2O3rammingmix,itwouldcausespallingofthefurnaceliningduringdrying-out.
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。
简介:本文综述了近年来有关锂离子电池正极材料尖晶石型LiMn2饥的制备与性能研究进展,重点讨论了尖晶石型LiMn2O4正极材料掺杂的最新研究现状,分析了该类材料的研究内容以及发展。
简介:本文采用固相反应法常压烧结制备MgNb2O6粉末,研究了添加不同质量分数的V2O5对MgNb2O6微波介电陶瓷的烧结丁艺和介电性能的影响。并运用XRD、SEM和LCR对试样显微组织和性能进行了分析。结果表明:添加一定量的V2O5能够有效地降低MgNb2O6介电陶瓷的烧结温度,提高试样的致密度、频率温度系数及介电常数。当V2O5添加量为1.0wt%,且在1175℃烧结条件下获得的MgNb2O6陶瓷性能最佳,其性能参数分别为:εr=28,tanδ=0.00361,τf=54.64ppm·℃^-1。
简介:TherearemanyprocessestoproduceCr2O3fromchrome-ores,DifferentparticlesizerangesofCr2O3powder,finepinmentgradegreenCr2O3andcoarsemetallurgygradeblackCr2O3,aremadebydifferentprocessesinChina,GreenCr2O3assuperfineandadditionandmetallurgygradeblackCr2O3usedtosynthesizeCr2O3graincanbeappliedtorefractories.ItisverydifficultforhighpurityCr2O3tosintertodensificationandTiO2additioniscontributedtodensificationofCr2O3sinteredathightemperature,Cr2O3grainswithrelativedensityof91%-95%aregainedbysinteringCr2O3withTiO2additionandelectrofusingCr2O3rawmaterials.
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简介:AnO'-Sialon-Al2O3compositerefractorywaspreparedbyinsitureactionofSi3N4-ZrSiO4-Al2O3mixturewithfusedaluminaaggregates.Densification,insitureactionprocedureandmicrostructureofthematerialwereinvestigatedbymeansofX-raydiffraction,opticalandscanningelectronicmicroscopesandEDAX.
简介:Siliconcarbide(SiC)-alumina(Al_2O_3)-mullite(Al_6Si_2O_(13))compositepowderwassuccessfullysynthesizedat1550℃for5hviacarbothermalreductionreaction,andtheeffectsofvariousmassratiosofactivecarbontoflyash(0.38,0.44and0.58)onthephasecompositionandmicrostructureofproductswereinvestigated,andtheformationprocessofthepowderwasalsoanalyzedindetail.Theproductsmainlyconsistofβ-SiC,α-Al_2O_3,Al_6Si_2O_(13)andFeSi.IncreasingcarboncontentfavorsthedecompositionofAl_6Si_2O_(13)andformationofSiC.Theaverageparticlesizeofβ-SiCandα-Al_2O_3isabout1μmandthatofAl_6Si_2O_(13)is5-10μm.TheformationprocessofSiC-Al_2O_3-Al_6Si_2O_(13)powderincludesthedecompositionofmulliteinflyashandformationofSiC.
简介:Themicrostructureandslagerosionfractaldimensionofreactioninterfaceofβ-Sialon-Al2O3brickusedin300MtironladleofBaosteelhavebeenstudiedbySEMandXRD.Theresultsindicatedthatβ-Sialon-Al2O3brickexhibitedexcellentslagresistance.Themainwearmechanismofβ-Sialon-Al2O3brickismainlyfromthespallingcausedbythermalmechanicalstressandattackedbyslagsecondly.
简介:Al2O3-MgOcastableshavebeenwidelyusedforworkingliningsofsteelladleduetotheirsuperiorhotstrengthandcorrosionresistance.Inthiswork,effectsofmicrosilica,ultrafinealuminaandMgOfinesadditionsontherheologicalbehaviorofthecastableswereinvestigatedbymeansofIBBrheometerV1.0tomeasuretorque(shearstress)undervaryingshearrates.Theresultsshowthatrheologicalpropertiesofcastablesatvaryingshearratesaresignificantlyimprovedwithincreaseofmicrosilicaadditions(from1mass%to5mass%)andcorrespondingdecreaseinwateraddition;thereisonlylittlechangeinrheologicalbehaviorwithvariationofultrafinealuminaandMgOfinesadditions.Optimumultrafinealuminaandmicrosilicaadditionsarerecommendedforcastableswithgoodrheologicalbehavior.
简介:TheinfluencesoffourkindsofadditivesaddedintothematrixofMgO-Al2O3unbunedproductswereinvestigated,TheresultsshowthatsampleswithproperMgO/Al2O3rationandproperadditionofCr2O3(2%-4%)havegoodthermalshockresistanceandslagcorrosionresistanceaswell,XRDandSEMdeterminationresultsindicatethatakindofcompoundspinel(Mg,Al,Cr)O4wasformedandthemicrostuctureofthesamplesaredenser.
简介:TiN-Al2O3compositepowderswithdifferentTiNcontents(0,10vol%,20vol%,30vol%and40vol%)werepreparedwithmicrometerTiNandα-Al2O3powder(theirpuritieswere99%)asstartingmaterialsbywetballmillingfor5h.TiN-Al2O3compositewerethenpreparedbypressingtheabovecompositepowders,dryingat200℃for12handfiringat1800℃for3hinnitrogenatmosphereinhot-pressingfurnace.TheinfluencesofTiNcontentonmechanicalpropertiesandelectricalconductivityofTiN-Al2O3compositeswerestudied.TheresultsshowedthatthemechanicalpropertiesofthecompositeincreasedwithTiNcontentincreasing,whiletheresistivityofcompositesdecreased.Acompositewith40%TiNhad498MPabendingstrength,4.285MPa·m1/2fracturetoughness,1.34×10-3Ω·cmresistivity.TheSEManalysisshowedthatthefineTiNcrystalsdistributedamongthecrystalboundaryofAl2O3matrix.Theybondedtogetherforminganet-likestructurewhichplayedaroleofrestrainingAl2O3grainsfromgrowingup,tougheningandstrengthening,sothemechanicalpropertiesofTiN-Al2O3compositewereenhanced.