简介:Hexagonplate-likeAl8B4C7powdersweresuccessfullysynthesizedusingamixtureofdiborontrioxide,activatedcarbonandaluminumoraluminabyacarbothermalreductionprocess.TheeffectofAlsourceandstartingmaterialsadditionsonsynthesisofAl8B4C7wasinvestigated.ThephasecompositionandmicrostructureofAl8B4C7powderwerecharacterizedbymeansofXRD,SEMandEDS.ThemainphasecompositionsoftheproductssynthesizedfromAl,B2O3andactivatedcarbonareAl8B4C7andAl2OC.Al2O3canreplaceAltosynthesizeAl8B4C7.Al8B4C7grainssynthesizedfromAl2O3,B2O3andactivatedcarbonarehexagonplate-likeandhaveathicknessof10μmandasizeofabout100μm.
简介:ZrN-basedcompositesweresynthesizedfromzirconiaviaaluminothermicreductionandnitridationproceswithAlpowdersandMgOasthereductantandsinteringaids,respectively.ZrN-basedcompositesarepromisingforapplicationintherefractorymaterialsorotherhightemperatureindustryfields.TheeffectsofextraAlpowderonphysicalproperties,phasetransformationandmicrostructureswereinvestigated.ProductswithdifferenphasecompositionandmorphologieswereobtainedwithdifferentAlpowdersadditions.TheproductswerecomposedofZrN,ZrO_2,MgAl_2O_4,andZrAl_3O_3Nbyaluminothermalreductionandnitridationofzirconiawith0%extraAlpowdersaddition.ThediffractionpeaksoZrNwerethestrongestwhilepeaksofZrO_2vanishedwith6%extraAladdition.ThethermodynamiccalculationindicatedthatintroducingMgOintothesystemcouldpromotethereactionprocess.