简介：TheeffectoftheadmixturesofAlandSimetalsandB4CandMgAlONcompoundsontheoxidationofMgO/Si3N4compositerefractoryhasbeenstudied,whichisapromisingcarbonfreerefractoryforsteel-makingapplicatlon.Thefourkindsofadmixturescanbeusedasanti-oxidantsforSi3N4,butthemixtureofAlandSiachievedthebestresult.Themixturecannotonlyplaytheroleasantioxidant,butalsoassistthesinteringprocessandhelpformdensesinteringlayer,improvingthepropertyofthecomposite.

简介：AkindofZrO2ceramicmaterialforporousmediaburnerwaspreparedbypolymericspongeprocesswithstartingmaterialsofzircon,zirconiapowder,microsilica,andballclay,andbinderofsilicasolthroughreaction-sintering.Theeffectsofmicrosilicaadditiononcoldcrushingstrengthandzirconia/zirconaddingratioonthermalshockresistancewerestudied.Theresultsshowthattheporousmediamaterialhasproperporosity,highstrength,andexcellentthermalshockresistancewhenzirconiaadditionis85%andzirconadditionis5%.Theperformanceindexesare:porosity82%,coldcrushingstrength3.1MPa,thermalshockresistancemorethan10cycles,andgoodthermalshockresistanceto1500℃flame.

简介：Inthis,phasecompsitionandthermalexpansionbehaviourofCaOStabilisedrefractorieswerestudied,Specialattentionwaspaidtotheexpasionbehaviourofthreematerialswithdifferentphasecomposition,TheresearchresultsindicatedthattheexpansionbehaviourcouldbeimprovedbymodifyingthestabilizationofZrO2,whichthusleadstotheincreaseinthethermalshockresistanceandpossiblyeroionresistaceofas-obtainedCaOstabilisedZrOmaterial.

简介：Inthispaper,X-raydiffractogramanalysisandSEMobservationofAl4C3formedathightemperaturefromcarbon-containingrefractorieswithAlhavebeencarriedout.Aluminumaddedtocarbon-containingrefractoriesreactswithC(s)toformAl4C3(s)graduallyduringheatingfrom600℃to1200℃.ItisconsideredthattheinterlockedstructureofAl4C3platecrystalspromotestheoutstandingincreaseofhotmodulusofruptureofcarbon-containingrefractorieswithAl.TheHMORofcarbon-containingrefractoriesaddedwithAladditivefrom0to5wt％increasesby2.8timesbeingfrom6.5MPato18.2MPa.AfterathermochemicalcalculationforhydrationreactionprocessesofAl4C3andH2O(g),theequilibriumpartialpressurechartofH2O(g)inH2O-Al4C3-Al(OH)3systemvsvarioustemperatureshasbeenattained.TheH2O(g)partialpressureintheairneededfortheAl4C3hydrationreactionisnomorethan10～18atmatthetemperaturebelow120℃.Itisconsideredthattheburnedcarbon-containingrefractorieswithAlisextremelyeasytohydrateandthecrackingofburnedcarbon-containingrefractoriesisgeneratedbecausethatthehydrationexpansionis2.11timesduringtransformingfromAl4C3toAl(OH)3.ThefundamentalmeasureagainsthydrationoftherefractoriesistoinsulatetherefractoriesfromH2O(g)byvariousmeanssuchaspitchimpregnationorothersealingmaterials.

简介：Zirconiagraphiterefractoryisusedasacore-nozzleinthethin-stripcastingofsteel.Post-mortemanalysisofusedrefractorywasperformedinanefforttoestablishthefailuremechanism.CorrosionbehaviorwasstudiedagainstmoltensteelwithMnO-SiO2basedliquidinclusions.CorrosionofthesematerialsinvolvesdissolutionandoxidationofgraphiteinthematrixfollowedbypenetrationofliquidslagleadingtodegradationofZrO2particles.Thermodynamicequilibriumcalculationswereperformedtostudythiscorrosionmechanism.

简介：O'-sialon-ZrO2compositebasedonthecheapcommercialavailablezirconandsiliconasrawmaterialscanbeachievedbyusingreac-tionnitridationmethod,Moreattentionwasgiventothenitridingprocessandtheeffectofadditivesonit.Theexperimentalresultsshowthattherearetwonitridationpaths:oneisthedirectnitridationofsiliconpowderandtheotheristhroughthereactionbetweenthemedi-umcompoundZrSi2andthenitrogen.Theeffectsofadditionofcalciaandtheincorpora-tionofBNonthenitridingreactionwerealsoinvestigated,theprimitiveexperimentalresultsdemonstratedthatbothofcalciaandBNcoulddeterioratethenitridingdegree.

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简介：IntheprocessofsynthesisofnanometerSiCprecursorswithsol-gelofSiO2andlignin,theproductsofallsizesrequiredcanbecontrolledbytheconcentrationofreac-tants,pH,temperature,ractionandageingtime,andsoon.Thebestconditionsinthisreserchare:theconcentrationofNa2SiO3andorganicmattersare4.50%and26.4%respectively,pH=3.3,T=65℃，ageingtimeis30min,driedat150℃，thesizeofSiCprecursorsisabout2.0μm。

简介：MoltensaltsynthesisofMgAl2O4powderfromindustrialaluminaandlightcalcinedMgOinKCl,LiCl,andKCl-LiClmedia,andtheinfluenceofKFat500-1000℃wereinvestigated.SynthesizedpowderswerecharacterizedbymeansofXRD,laserparticleanalyzer,andSEM,andthesynthesismechanismofMgAl2O4wasdiscussedaswell.Theresultsshowthat(1)themoltensaltcomposite(KCl-LiCl)ismorefavorableforthesynthesisofMgAl2O4thansinglemoltensalt(LiClorKCl),andLiClismorefavorablethanKCl;(2)KFcanacceleratetheformationofMgAl2O4anddecreaseitsformingtemperature;(3)synthesisofMgAl2O4powderinthemoltensaltswithoutKFiscontrolledby'template-growth'mechanism,butinthemoltensaltswithKF,itiscontrolledby'template-growth'and'dissolution-precipitation'mechanism.

简介：InordertoimprovethemechanicalpropertiesofSiO2aerogel-glassfibercomposites,effectsofdifferentsolvents(cyclohexane,n-hexane,ethanol,acetone)anddifferentdispersingmodes(planetaryballmilling,ultrasonicdispersionandmechanicalstirring)anddispersingduration(10-40min)onthedispersionofchoppedalkali-freeglassfiberbundleswerestudiedtodeterminethebestdispersionprocess.Onthisbasis,thematerialswerebatchedaccordingtothemassfractionofSiO2aerogelpowdertochoppedalkalifreeglassfiberbundlesof90:10,andacertainamountofzincoxidelight-screeningagentandphenolicresinbinderwereadded.SiO2aerogelglassfibercompositespecimenswerepreparedbydirectaddingchoppedalkalifreeglassfiberbundlesandpre-dispersedchoppedalkalifreeglassfiberbundles,respectively.Thecoldcrushingstrengthandthethermalconductivityatdifferentsurfacetemperatures(300,400,500and600℃,respectively)ofthespecimensweremeasured.Theresultsshowthat:(1)theoptimumdispersionprocessofchoppedalkali-freeglassfiberbundlesisusingethanolassolventandmechanicalstirringfor30min;(2)pre-dispersionofchoppedalkali-freeglassfiberbundleshaslittleeffectonthethermalconductivityofSiO2aerogel-glassfibercompositesbutcanimprovethecoldcrushingstrength.

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简介：Theroleofnano-SiO2andultra-fineboroncarbideonthepropertiesofalumina-graphitematerialswasinvestigated.Thestudyshowedthattheultra-fineboroncarbideaddedmodifiedthemicrostructureofresidualcarbonandpromotedthechemicalbondbetweenresidualcarbonfromphenolicresinandflakegraphite.Thecarbonwhitecouldstrengthentheresidualcarbonfromphenolicresin.ThesetwoadditivesimprovedthemechanicalpropertiesofAGrefractoriesatbothroomtemperatureandhightemperature,andthermalshockresistancewasimprovednoticeably.Whenthetwoadditivesweredopedtogether,carbonwhitecouldretardtheevaporationofB2O3.Thermalshockresistancewasguaranteedwithasmalleramountofultrafineboroncarbide.

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