简介:Hexagonplate-likeAl8B4C7powdersweresuccessfullysynthesizedusingamixtureofdiborontrioxide,activatedcarbonandaluminumoraluminabyacarbothermalreductionprocess.TheeffectofAlsourceandstartingmaterialsadditionsonsynthesisofAl8B4C7wasinvestigated.ThephasecompositionandmicrostructureofAl8B4C7powderwerecharacterizedbymeansofXRD,SEMandEDS.ThemainphasecompositionsoftheproductssynthesizedfromAl,B2O3andactivatedcarbonareAl8B4C7andAl2OC.Al2O3canreplaceAltosynthesizeAl8B4C7.Al8B4C7grainssynthesizedfromAl2O3,B2O3andactivatedcarbonarehexagonplate-likeandhaveathicknessof10μmandasizeofabout100μm.
简介:EffectofrareearthoxideonpropertiesofCaO-MgO-SiO2systembio-solubleceramicfibers.WangXitang,LiuHao,ZhangBaoguo,etal.(321-324).-Rareearthoxide,Ceramicfiber,Bio-solubility,Crystallizationbehavior-CaO-MgO-SiO2systembio-solubleceramicfibersweremadebymelting-spinningprocessusingnaturalwollastonite,talc,andquartzsandasmainstartingmaterials,andrareearthoxideasadditive.Theviscosityofthemelts,bio-solubilityandcrystallizationbehaviorathightemperaturesoftheceramicfiberswereinvestigated.Theresultsindicatethattheintroductionofrareearthoxide:(1)broadsthefiber-formingtemperaturerange;(2)reducesthesolutionspeedofCaO-MgO-SiO2systembio-solublefibersinlungliquidbutdoesn'tchangethebio-solubleattribute;(3)strengthensthenetworkstructureofthefibersandrestrainsthecrystallizationbehaviorathightemperatures.
简介:Theroleofnano-SiO2andultra-fineboroncarbideonthepropertiesofalumina-graphitematerialswasinvestigated.Thestudyshowedthattheultra-fineboroncarbideaddedmodifiedthemicrostructureofresidualcarbonandpromotedthechemicalbondbetweenresidualcarbonfromphenolicresinandflakegraphite.Thecarbonwhitecouldstrengthentheresidualcarbonfromphenolicresin.ThesetwoadditivesimprovedthemechanicalpropertiesofAGrefractoriesatbothroomtemperatureandhightemperature,andthermalshockresistancewasimprovednoticeably.Whenthetwoadditivesweredopedtogether,carbonwhitecouldretardtheevaporationofB2O3.Thermalshockresistancewasguaranteedwithasmalleramountofultrafineboroncarbide.