简介：Calciumhexaluminate(CA6)wassynthesizedbymixinglight-weightcalciumcarbonateandAl2O3micropowder(calcinedα-Al2O3,activatedα-Al2O3orρ-Al2O3)accordingtothestoichimetricratioofCA6,andreactionsinteringat1200,1300,1400and1500℃for3h,respectively.Effectsofthethreealuminamicropowdersonthephasecomposition,microstructureandpropertiesofCA6wereinvestigated.Theresultsshowthat:(1)forthethreeAl2O3micropowders,thereactiontogenerateCA6inspecimensbasicallycompletesatabout1500℃;CA6generatedinallspecimensisplanar,butthearraymodesareslightlydifferent;(2)thespecimenspreparedfromcalcinedα-Al2O3orρ-Al2O3shrinkalmost,whilethespecimenspreparedfromactivatedα-Al2O3expand;(3)thecoldcrushingstrengthofthespecimenpreparedfromactivatedα-Al2O3isthehighest,reaching42.5MPawhenonlyCA6exists(afterfiringat1500℃);(4)thespecimenpreparedfromρ-Al2O3hasthelowestgenerationtemperatureofCA6andthehighestapparentporosity,reaching70.1%whenonlyCA6exists(afterfiringat1500℃);(5)thespecimenpreparedfromcalcinedα-Al2O3hasthebiggestbulkdensity.

简介：ThechromiumoxidematerialswerepreparedusingCr2O3micropowderasmainstartingmaterial,TiO2micropowderassinteringaid,polyvinylalcoholasbinder,byaseriesofprocessessuchasslurrying,sprayinggranulation,machinemouldingandcoldisostaticpressing,andfiringat1500℃for3hinair(oxygenpartialpressurewas2.1×104Pa),industrialnitrogen(oxygenpartialpressurewas1×103Pa),purenitrogen(oxygenpartialpressurewas10Pa),highpuritynitrogen(oxygenpartialpressurewas0.1Pa),andcarboncakeembeddedatmosphere(oxygenpartialpressurewas2.3×10-12Pa).EffectsofoxygenpartialpressuresonthesinteringbehaviorofCr2O3materialswereinvestigated.Theresultsshowthat(1)for3wt%TiO2-dopedspecimens,thereisasubstantialdependenceofsinteringonoxygenpartialpressure(0.1Pa-2.1×104Pa),andthebulkdensityincreasesandapparentporositydecreaseswithoxygenpartialpressuredecreasing;(2)eveniftheoxygenpartialpressureis0.1Pa,thespecimenwithoutTiO2cannotreachdensificationsintering;(3)underverylowoxygenpartialpressureofcarbonembeddedatmosphere,Cr2O3materialscontainingTiO2ornotcanattaindensification.

简介：BauxitefromQingzheniscalcinedforrefractoriesapplications.Threefuelsourceswithdifferentamountsofresidualashandferricoxidewereusedforbauxitecalcinationinarotarykiln.Itisfoundthequality,includingthecontentofferricoxide,bulkdensity,apparentporosityandwaterabsorption,ofthebauxiteishighlyinfluencedbythefuelsourceofrotarykiln.Inessence,theeffectoffuelonthequalityofbauxiteisattributedtotheamountofferricoxideintroducedbythefuel.Introductionofamodestquantityofferricoxideisbeneficialforpromotingthedensificationofbauxite.

简介：SinteringadditivestogelcastingSialon-SiCweredecidedbytheoptimizingexperiments.TheresultsshowthatSoalon-SiCcanbesinteredunder1450℃andsinteringtemperaturedecreasesby100℃,when2%～3%TiO2orGuangxiclayisusedassinteringadditive.

简介：ThepaperdescribestheeffectofadditivesAl,Si,SiCandB4ContheexpansionofMgO-ZrO2-Cmaterialafterbeingcoked.TheresultsindicatethatAlandSicannotincreaseitshotandcoldstrength.AlandSiwereoxidizedtoformAl2O3andSiO2respectively,andthenreactedwithCaZrO3orstabilizerinc-ZrO2toformcalciumaluminate,spinel(MA),dicalciumsilicate(C2S)andforsterite(M2S).Meanwhile,α-C2Swastransformedtoγ-C2Sandc-ZrO2tom-ZrO2whentemperaturechanged.AlltheabovereactionsresultedinthedecreaseoftheamountofAl4C3andSiCandtheincreaseinbulkvolume,whichcausedthestructureofMgO-ZrO2-Cmaterialdestroyed.Hence,contrarytotheMgO-Cmaterial,whenaddingAl.andSi,theMgO-ZrO2-Cmaterialwouldbestructurallydeterioratedafterheat-treatmentanditsstrengthandcorrosionresistancedecreased.

简介：EffectofthecontentofLa2O3,CeO2andSiO2onthesinteringbehaviorandmicrostruc-tureofAZS-40materialhasbeenstudiedbymeansofsinteringtestandSEMexamination,TheresultsshowthattheporosityoftheAZS-40clinkerwithadditionof0.5%La2O3orCeO2couldreach2%undertheonditionof1600℃for4hours.Butitisnotbeneficialtothesinteringandmicrostructureoftheclinkerswhentheadditionoftherareearthoxidesincreasestomorethan0.5%,AZS-40materialsbecomedifficulttobesinteredastheadditionofSiO2inthematerialsincereases.

简介：Theeffectofpressdirectiononthethermalexpansion,slagresistance,etc.ofpericlase-spinel-carbonbrickhasbeenstudiedinthisarticle.Theresultsshowthatthetherma1expansionrateinthedirectionparalleltothepressaxisislargerthanthatinthedirectionperpendiculartothepressaxisandtheslagresistanceinthedirectionparalleltothepressaxisismuchbetterthanthatintheperpendiculardirection.Thedirectionaldistributionofgraphiteinthespecimenisobservedwiththemicroscope.

简介：ThemagnesiabasedcurablespecimenswithdifferentSi3N4contentswerecastedusingsinteredmagnesite(w(MgO)=95%)asstartingmaterial,SiO2micro-powderasbinder,0.3%,4%and5%β-Si3N4powderreplacingtheequaladditionofmagnesiapowderrespectively.Theslagresistancetestwascarriedoutat1550℃for3husingBaosteeltundishslagandstaticcruciblemethod.Theresultindicatesthat:introducingSi3N4couldobviouslyimprovetheslagresistanceofMgObasedcastable,whichincreasedwithincreasingSi3N4.DenseSiO2sinteredlayerformedonthesurfaceofmagnesiabasedcastablebecauseoftheoxidationofSi3N4addition,whichcanpreventthefurtherslagpenetration.Inthedeepinnerofcastable,thepartial-pressureofoxygenwasverylow,soSi3N4canexiststably.Meanwhileinreducingatmosphere,Si3N4washardtobesintered,whichresultedinthelooseinteriorstructureofMgObasedcastable.

简介：

简介：TheeffectofTi(C,N)onpropertiesoflow-carbonMgO-Cbrickswasinvestigated.Thephasecompositionandthemicrostructureofthematrixoflow-carbonMgO-CbrickcontainingTi(C,N)werestudiedbyXRDandSEManalysistogetherwithEDS.TheresultsshowedthatTi(C,N)distributedinthematrixoflow-carbonMgO-Cbrickuniformlyafterbeingtreatedat1600℃for3hincokepowderbed,andTi(C,N)andMgOformedasolidsolution.Afterthetreatmentat1600℃for3hincokepowderbed,thebulkdensityandcoldcrushingstrengthoflow-carbonMgO-CbrickwithTi(C,N)decreased,andtheapparentporosityandlinearchangerateofspecimensincreased.Theoxidationresistanceoflow-carbonMgO-CbrickwithTi(C,N)wassuperiortothatoflow-carbonMgO-Cbrickwithnoadditives,butinferiortothatoflow-carbonMgO-CbrickwithAlpowder.TheslagresistanceofthespecimenwithTi(C,N)wasexcellentaswell.

简介：

简介：Hexagonplate-likeAl8B4C7powdersweresuccessfullysynthesizedusingamixtureofdiborontrioxide,activatedcarbonandaluminumoraluminabyacarbothermalreductionprocess.TheeffectofAlsourceandstartingmaterialsadditionsonsynthesisofAl8B4C7wasinvestigated.ThephasecompositionandmicrostructureofAl8B4C7powderwerecharacterizedbymeansofXRD,SEMandEDS.ThemainphasecompositionsoftheproductssynthesizedfromAl,B2O3andactivatedcarbonareAl8B4C7andAl2OC.Al2O3canreplaceAltosynthesizeAl8B4C7.Al8B4C7grainssynthesizedfromAl2O3,B2O3andactivatedcarbonarehexagonplate-likeandhaveathicknessof10μmandasizeofabout100μm.

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℃.

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简介：MgO-ZrO2unfiredbrickswithZrO2contentupto8%attheintervalof2%wereprepared,usingfusedmagnesia(MgO:97%)andfusedMgO-ZrO2clinker(ZrO2:14.33%)asstartingmaterialsandphenolicresinasbinder.TheeffectsofZrO2contentonthermalshockresistance(TSR)andotherpropertiessuchascoldandhotmodulusofrupturehavebeeninvestigated.Residualcoldmodulusofruptureratioafterheatingat1000℃andquenchingbyairblowingwasadoptedtocharacterizeTSR.AdditionoftheMgO-ZrO2clinkerimprovesTSR,attributingtothemicrocracktougheningeffectbythermalexpansionmismatchbetweendifferentphases.WhenZrO2contentgoesabove4%,theimprovingeffecttendstobemoderate.TheintroductionofMgO-ZrO2clinkercanalsoimprovetheHMORat1500℃,whiletheincreasedZrO2contentreducesCMORofthebricksprefiredat1600℃,duetothethermalexpansionmismatcheffect.Compromisingtheoverallproperties,theoptimalZrO2contentforsuchmagnesiabasedunfiredbrickissuggestedtobe4%.

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.