简介：Simplethree-pointbendingtestatambienttemperaturecharacterizedthemechanicalbehaviorofburnedAl2O3-Crefractoriesbeforeandafterthermalshockinassociationwiththeprocessingparameters(graphitecontentandcokingtemperature,etc.).Theresultsshowedthatnon-linearplastic-elasticbehaviorunderloadlowerthancoldmodulusofrupture(CMOR)wasregisteredinallspecimensandreallinearelasticbehaviorcouldbeidentifiedafterthefirstload.Thetotaldeformationcouldbedividedintotwoparts,plasticandelasticareas.ThegraphitecontentandjointbondingsystemofcarbonandceramicphaseswereresponsibleformechanicalbehaviorofAl2O3-Crefractories.

简介：

简介：UsingAl2O3-MgOcastableinlargeladlecanavoidcontainationofmoltensteelfromcarbon-containingrefractoriesandincreasladleservicliferemarkably,Theadditionofmagnesiaandfinepowder,theeffectofgrainsizeontheproper-tiesofthecastable,especiallylinearchangeandstructurespallinghavebeenstudied,Castablepro-duedforlargeladlewithsmallweareratehasgotgoodapplicatioresult.

简介：Inthisstudy,inordertoevaluatetheperformanceofhomogenizedbauxite,twoAl_2O_3-SiC-Ccastableswerepreparedusinghomogenizedbauxiteandbrownfusedcorundumasaggregates,respectively.5mass%andalusitewasintroducedintothetwocastablessoastoresearchtheeffectandmechanismofandalusiteinAl_2O_3-SiC-Ccastables.Theresultsshowedthat:(1)comparedwiththebrownfusedcorundumbasedcastables,thehomogenizedbauxitebasedcastableshadhighercoldstrengthafterheattreatment,butlowerhotmodulusofrupture;(2)additionof5mass%andalusitecouldenhancethecoldandhotmodulusofrupture,improvethethermalshockresistance,andoptimizethemicrostructureofspecimens;(3)themullitizationofandalusitewasnotobviousinthecastablesfiredat1100-1400℃.

简介：ThispapertestifiesthataluminiumandsiliconaswellastheircarbidexandnitridescanreactwithCOincarbon-containingzonetoformAl2O3andSiOgasthroughexperimentandthermodyanmicanalysis,ThegasesdiffusetooxidizedzoneandreactwithoxidizerssuchasCO2,Asaresult,Al2O3andSiO2aredepositedfromthegases,wihichblockthepores,thusreducetheamountofgasdiffusionandincreaseoxidationresistnaceofcarbon-containingmaterials.

简介：SiliconoxynitridewasaddedinshapedAl2O3-SiC-Crefractorymaterialtoimprovetheslagresistanceinthispaper.Optimumaddingquantityofsiliconoxynitridepowderwasalsostudied.TheresultsshowthattheslagresistanceofAl2O3-SiC-Cshapedrefractoryisimprovedwhen2%or3%Si2N2Oisadded.AreasonableamountofSi2N2OaddedintoAl2O3-SiC-Cshapedrefractorycanproducesiliconoxideintotheslag,whichcanimprovetheviscosityofslagandpreventtheslagerosionandpenetration.

简介：Thecorrosionofrefractoriesresultsfromreactivetransport,namely,transportofagentsandchemicalreactionsoftheseagentswithimpregnatedmedium.Ononehand,thetransportinvolveseitherdiffusionorimpregnationdependingonthestateofthecorrosiveagentsandthemicrostructureofthehostmedia.Ontheotherhand,chemicalreactionsmaybeverynumerousandcomplex.ThisstudyfocusedonthereactiveimpregnationofAl2O3-CaOslagintoporoushighaluminarefractory.Thetransportpropertiesoftherefractorymaterialwereidentifiedbymeansofadedicatedcapillaryrisingtest.ChemicalreactionsbetweenthesolidhighaluminaskeletonandAl2O3-CaOslaginvolvesuccessivedissolution/precipitationmechanismsformingaluminatesoflime.Contrarytothethermodynamicpropertiesofthebinarysystem,thekineticsofthesesolid/liquidreactionsisnotwellknown.Corrosiontestsassociatedwiththequenchingmethod,XRDanalyseswereperformedforabetterunderstandingofthekinetics.Theresultsofthisstudyopenupacouplingapproachforpredictingthecorrosionwearofrefractory.

简介：

简介：

简介：β-sialon/alumina/silicamixturesweresinteredinflowingnitrogenat1500℃and1600℃respectively.ThesinteringpropertiesandmorphologyofsampleswereinvestigatedbySEM,EDSandXRD.Resultsshowthatsinteredpropertiesofthesamplesareinfluencedbysoakingtemperaturesandcompositions.Bulkdensitiesofsamplesareincreasedwiththeincreaseofthesoakingtemperature,whereastheapparentporositiesaredecreased.Masslossofthesinteredsamplesat1500℃islowerthanthatat1600℃,butallthemasslossremainsapproximatelyconstantwiththeincreaseofsialoncontent.Fromthepointofthermodynamicanalysis,ComplexchemicalreactionstakeplaceinsamplesduringsinteringprocessandthevolatileofSiO(g)isresponsibleforthemasslossofsamples.Comparedtocrosssectionmicrostructureofβ-sialon/Al2O3/SiO2mixturessinteredincokepowderbedconsistingofthedensecenterwithwell-developedcolumnofsialonphase,thetransitionalpartwithneedlelikegrainnitrogen-containingphaseandtheloosepartwithshortgranularAl2O3phase,thoseofmixturessinteredinflowingnitrogenisofwell-developedsialonindensecenterandslightlyloosepartwithsialondebris.

简介：MicrostructureandgrainboundarycharacterofhotpressedbinaryAl2O3(mullite,ZrO2)-SiCompositesandquaternaryAl2O3-mullite-ZrO2-SiCcompositewerestudiedbyelectronmicroscopyandmicroanalysis,ResultssuggestthatthereexistgrainboundarysolidsolutionsduetoelementaldiffusionnearSiCandmatrixoxidesgrainboundaries.

简介：LowcementAl2O3-SiO2castableswaspreparedusingsupergradebauxite(w(Al2O3)>85%)asaggregate,brownfusedcorundum,siliconcarbide,Secar71CAcement,α-Al2O3micropowderandmicrosilicaasfinepowders.TheinfluenceofSiC(0,5wt%,10wt%,and15wt%)onresistancetoPbO-richslagwasinvestigatedbystaticcrucibleslagtest(1300℃for5h,inair).TheslagcorrosionmechanismofthecastableswasanalyzedbymeansofSEM,EDSandXRD.TheresultsshowthattheresistanceofAl2O3-SiO2castablestoPbO-richslagisimprovedobviouslybytheadditionofSiC.ThecorrosionmechanismofthePbO-richslagcanbediscribedasthatPbOintheslagreactswithSiO2andCaOinAl2O3-SiO2castables,forminglow-meltingcompounds(suchasPbO·SiO2and2PbO·SiO2).

简介：MgO-Al2O3-Cr2O3rammingmixesmadeofdifferentrawmaterialshavedifferentmineralstructureanddifferentphysicalpropertiesthoughwiththeidenticalparticlesizedistribution,thesameamountofbinderandchemicalcomposition.Theresidualcarboncontentofthefusedmagnesia-chromematerialmadeinreducingatmosphereisveryhigh,ifthismaterialsisusedintheMgO-Al2O3-Cr2O3rammingmix,itwouldcausespallingofthefurnaceliningduringdrying-out.

简介：

简介：Thisworkinvestigatedthethermo-gravimetric(TG)changeandexplosionresistanceofultra-lowcementAl2O3-SiO2castablesaddedwith0,5%,10%,15%and20%of≤74μmrawbauxitepowderscontaining72.8%Al2O3,respectively.Thecastableswerepreparedusingwhitefusedaluminaasaggregate,powdersofwhitefusedalumina,fusedmullite,α-Al2O3ultrafines,3%CAcementand5%microsilicaasthematrixportion.TGchangeofthecastableswasinvestigatedbyathermo-gravimetricanalyzerforlargesizespecimen.Whentherawbauxiteadditionislessthan10%,themass-losingbehaviorofthecastablesissimilartothatwithoutrawbauxite,tendingtoreachaconstantmassaround400℃,beforewhichthemass-lossismildandproducinglittledestructiveinfluence.Withmorethan10%rawbauxiteaddition,however,themass-lossincreasessignificantly,andthetemperaturetoreachaconstantmassincreasesto600℃orhigher,unfavorabletostructuralstabilization.Withtherawbauxiteadditionupto20%,nonegativeinfluenceonexplosionresistanceisfound.

简介：

简介：AnO'-Sialon-Al2O3compositerefractorywaspreparedbyinsitureactionofSi3N4-ZrSiO4-Al2O3mixturewithfusedaluminaaggregates.Densification,insitureactionprocedureandmicrostructureofthematerialwereinvestigatedbymeansofX-raydiffraction,opticalandscanningelectronicmicroscopesandEDAX.