简介:Onthebasisofthetheoryofthermalshockresistanceinthescienceofmaterialsandthetestmethodofairquenchingwhichisgenerallyrec-ognizedinternationally,especiallyinEurope,thepresenttestmethodsfordeterminationofthermalshockresistanceinChinahavebeenanalysed,Experimentstudyonthermalshockresis-tanceofsilicaandbasicrefractoryproductshasbeenconducted,andanewtestmethodofthermalshockresistance-airquenchingmethodhasbeenputforward.
简介:YB/T384-20111ScopeThisstandardspecifiestheclassification,technicalrequirements,testmethods,qualityappraisalprocedures,packing,marking,transportation,storage,andqualitycertificateofsilicarefractorymortars.Thisstandardisapplicabletosilicarefractorymortarsforliningsilicabricks.2NormativeReferencesThefollowingdocumentsareessentialtotheapplicationofthisstandard.Fordatedreferences,onlytheeditioncitedapplies.
简介:Thermalshockresistantpropertiesofreactionsinteredbauxite-basedβ-Sialonbondedcorundumhavebeeninvestigated,andtheresultsarecomparedwiththoseofAl2O3basedcounterpart.Itisfoundtheyallhaveverygoodthermalshockresistance.Theirresidualstrengthratiosafteronethermalshockcycleat△T=1200℃and△T=1350℃are61%~73%and53%~65%respectively.Theircriticaltemperaturedifference(TSR)is600℃~800℃.TSRparametersarecalculatedbasedonthermalexpansion,modulusofelasticity,andfracturetoughnessdetermined.ThereasonsforimprovingTSRofthesecompositematerialsarediscussed.
简介:Inthis,phasecompsitionandthermalexpansionbehaviourofCaOStabilisedrefractorieswerestudied,Specialattentionwaspaidtotheexpasionbehaviourofthreematerialswithdifferentphasecomposition,TheresearchresultsindicatedthattheexpansionbehaviourcouldbeimprovedbymodifyingthestabilizationofZrO2,whichthusleadstotheincreaseinthethermalshockresistanceandpossiblyeroionresistaceofas-obtainedCaOstabilisedZrOmaterial.
简介:Refractorymaterialsaresubjectedtomechanicalandchemicalloadsduringapplication,whichrespectivelyleadtofractureandcorrosion.Theunderstandingofthemechanicalfractureandthemicrostructuralmodificationafterprogressivethermalshocksisnecessaryforthesuitabledesignofhighperformancerefractorymaterials.Thefractureprocesszonecanbedividedintotwoareas,wheredifferenttougheningmechanismsarelikelytotakeplace:thecracktipandthefollowingprocessregioncalledwakeregion.Inthisstudy,theemphasisislaidonthemicrostructuralmechanismsoccurringinthewakeregionofthecrackandthecracktip.Therefore,functionalaggregates,namelyfusedeutecticaggregatesofAl2O3-ZrO2-SiO2andAl2O3-ZrO2,andandalusite,areaddedtoamodelhighaluminacastableformulationbasedontabularalumina.Thediscrepancyinthermalbehaviorbetweenaggregatesandmatrixaswellasphasetransformationsuchasmulliteformationfavorfurtherthenucleationofmicrocracksthatreducethestressfieldatthelevelofthecracktip.Twodifferentgrainfractionsoftabularalumina(0.2-0.6mmor2.24-3.00mm)aresubstitutedbythesefunctionalaggregates.Aftersinteringat1500℃for6h,thesamplesarequenchedupto10timesinairwithoutpressurefrom950℃toroomtemperature.Theresultingelasticpropertiesareexaminedaftereachthermalshockcycle,aswellastheresidualbendingstrengthafter0,1,3,5,7and10thermalshocks.TheseresultsarecorrelatedwithScanningElectronMicroscopyanalysesafterthedifferentthermalshockcycles.
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.