简介:BycarbothermalreductionofMgOwithblackcarbonasreductionagentatahightemperature,MgOwasdepositedonthesurfaceofMgO-CaOclinker(ascoating)toimprovetheclinker'shydrationresistance.Inthepaper,effectofdepositiontemperatureandholdingtimeonthehydrationresistanceofthetreatedMgO-CaO,thedepositionmechanismandMgOcoatingkineticswereinvestigatedwithhydrationresistancetest,X-raydiffractometry(XRD)andscanningelectronicmicroscope(SEM).ResultsshowedMgOcoatinggrewina2DmodeonthesurfaceofMgO-CaOparticles;theMgOcoatingimprovedthehydrationresistanceofthecoatedMgO-CaOclinker,andthecoatedclinkerwouldbecomestrongerwhencoatedathigherdepositiontemperatureandlongerholdingtime.ThemeasurementsalsofoundthatMgOdepositionprocessvariedwiththedepositiontemperature:itwasmainlyachemical-controlledprocessattemperaturesbetween1400-1500℃,withanapparentactivationenergy(AAE)of97.8kJ·mol~(-1);itwouldchangeintoadiffusion-controlledprocesswhenthetemperaturerisingto1500-1600℃,withapparentactivationenergyof19.2kJ·mol~(-1).
简介:Thedevelopmentstatus,productiontechnologyandcharacteristicsofMgO-CaOrefractoriesareintroduced,coveringMgO-CaOclinkers,firedMgO-CaObricksandunburnedMgO-CaO-Cbricks.TheapplicationsofMgO-CaOrefractoriesinsecondaryrefiningfurnacesincludingAOD,VOD,LF-VDandGORareintroduced.
简介:OnthebaseofMgO-CaOcoatingmaterialTD-CA12fortundish,anewTD-CA32withhighCaOcontentwasdeveloped,ItsCaOcontentis30%-36%andMgOcontentis45%-55%,TheapplicationresultinBaosteelshowsthatTD-CA32notonlyhasthesamepropertiesasTD-CA12butalaohastheimprovedpropertiesofdisintegrationandsteelpurifing.
简介:摘要:采用固相烧结法制备了复合钛酸镁介质材料xMg2TiO4-(0.95-x)MgTiO3-0.05CaTiO3,数据表明,随着x增大,介电常数呈现降低趋势,频率温漂系数变负,同时品质因数呈现先增大后减小趋势,当x=0.20时,对应介质陶瓷Er=20.34,Q·f=72153,Tf(25~85℃)=-3.75ppm/℃。为使频率温度系数更接近零,探究了0.2Mg2TiO4-0.75MgTiO3-yCaTiO3体系y变化的影响;数据表明当y=0.056时,Er=20.50,Q·f=69768,Tf(25~85℃)=0.94ppm/℃,其Q·f值远高于0.95MgTiO3-0.05CaTiO3体系,具有较好的应用前景。
简介:Thedependenceofperpendicularmagneticanisotropy(PMA)onthebarrierlayerMgOthicknessinMgO/CoFeB/Tamultilayersisinvestigated.TheresultsshowthatthestrongestPMAoccursinasmallwindowofabout2-4nmwiththeincreaseofMgOthicknessfroml-10nm.ThecrystallinedegreeofMgOandthechangeofinteratomicdistancealongtheout-of-planedirectionmaybethemainreasonsforthechangeofPMAinthesemultilayers.Moreover,theroughnessesof2-and4-nm-thickMgOsamplesare3.163and1.8nm,respectively,andboththesamplesshowPMA.TheseresultscouldbeusedtotunethemagneticcharacteristicoftheultrathinCoFeBfilmforfutureapplicationsinperpendicularmagneticdevices.