简介：Aluminamagnesiacastablecruciblespecimenswerepreparedusingtabularcorundum(≤5mm),fusedmagnesiapowder(≤0.088mm),fusedspinelpowder(≤0.044mm),andα-Al2O3micropowder(d50≤0.7μm)asmainstartingmaterials,batching,mixing,shaping,anddrying.Slagresistancewasdeterminedbystaticcruciblemethodat1600℃for3hadoptingtwoladleslagswithdifferentbasicities(3.40and1.03).Thecorrosionandpenetrationindexesandmicrostructurecharacteristicsofthespecimensafterslagresistancetestwereanalyzedtostudythecorrosionbehaviorsofthetwoslagstoaluminamagnesiacastables.Theresultsshowthatthecorrosionofthelowbasicityslagtoaluminamagnesiacastablesismuchmoreseriousthanthatofthehighbasicityslagforthattheirreactionswithcastablesformdifferentproducts;forthelowbasicityslag,themulti-phasecoexistenceofCA6andcompoundsofCaO-Al2O3-SiO2inthematerialstogetherwithvolumeexpansioncausedbytheformationofCA6intensifytheslagcorrosionandpenetration;forthehighbasicityslag,thereactionbetweenslagandcastablesgeneratesaCA2denselayerandalargeamountofin-situMAintheinterface,reducingtheslagcorrosiontothematerialseffectively.

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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.