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

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：

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.

简介：

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

简介：

简介：TheinfluenceofthreedifferentAl2O3powderonself-flowingaluminacastablewasstudied.MaximumcompactionofsamplewascomputedbyAndresenEquation.TheresultshowedthattheAl2O3powder,whichhasmuchsmallerparticlesize,couldimprovethemicrostructureandthemechanicalpropertiesofcastableunderroomtemperatureandhightemperature.Withthesamepowdersize,theroomtemperaturestrengthofthecastableaddedwithAl2O3powderproPertiesofwhichwerealteredbyaddingmineralizingagent,washigherthanthatofthecastableaddedwithcommonAl2O3powder,buttheflowabilityofthesethreedifferentcastablewasalmostthesame.

简介：Thestabilizationofγ-aluminiumoxyni-tridespinel(γ-AlON)hasbeeninvestigatedbyadditionofMgO,MgAl2O4,etc.,inreactionprocess.Theresultsindicatedthattherearewidersolidsolutionareasnear,Al2O3-richsideinAlN-Al2O3-MgOternarysystems,ThecontentofstabilizedAlONphaseinsamplesisrelatedtoheatingtemperatures,additives,etc.ThelatticeparametersoftheirAlONphasescouldbewelldescribedbytheequation:a0=0.7900+0.0375[MgO]+0.015[AlN](nm)

简介：

简介：Inordertoimprovetheservicelifeofcorundumliningforinductionfurnace,corundumdryrammingmixwaspreparedusingbrowncorundum,fusedmagnesia,andα-Al2O3micropowderasmainstartingmaterials,andtheinfluenceofα-Al2O3micropowderadditions(0,1%,2%,and3%,inmass)onpropertiesofcorundumdryrammingmixwasinvestigated.Theresultsshowthatafterheattreatingat1600℃,withtheincreaseofα-Al2O3addition,thepermanentchangeindimensionsonheatingofthespecimensdecreasesfirstlyandthenincreases,bulkdensityincreases,apparentporositydecreases,andthecrushingstrengthdeclinesfirstlyandthenenhances;whentheadditionofα-Al2O3is2mass%,thepermanentchangeindimensionsonheatingofthespecimensisrelativelysmallandthecrushingstrengthdecreasesto22.8MPa.TheXRDandSEMresultsshowthatafterfiringat1600℃for3hsmallgranularmagnesiumaluminatespinelformsandiswelldistributed,whichenhancesthedensity.

简介：TheAl2O3-SiCcompositepowderswerepreparedinargonatmosphereusingcoalgangueandcarbonaceousmaterials2O3-SiCcompositepowderswereinvestigated.Theresultsindicatethat:temperature,soakingtimeandchlorideadditivehavesignificantinfluenceonthesynthesizedAl2O3-SiCcompositepowders.Basedontheresults,theoptimizedAl2O3-SiCcompositepowders（Al2O358mass%andSiC42mass%）withparticlesized50≤5μmwerepreparedusingcoalgangueandcarbonblackasstartingmaterialsafter3hfiringat1550℃.andproperadditiveadditioncouldreducethetemperatureby50℃.

简介：Thekineticprocessofslagcorrosionforβ－Sialonandβ-Sialon-Al2O3compositeshasbeenstudiedbymeansofdipmethod(staticandself-rotating),Thecorrosionmodelisbuitlandtheformulaofcorrosionrateisdeduced,whichareinaccordancewithexperimentalresults.

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