2013年《硅酸盐学报》英文模板_doc

原位反应法制备Cr2AlC-Fe复合材料陈新华，翟洪祥，王文娟，黄振莺(北京交通大学，北京100044)摘要：采用原位反应法制备了Cr2AlC-Fe系复合材料，并采用热分析、X射线衍射、扫描电子显微镜和三点弯曲实验，研究了原位反应的烧结工艺对产物和显微结构的影响，以及对原料中Cr2AlC的含量对复合材料性能的影响。结果表明：通过高温原位反应，原料中Cr2AlC发生了分解，形成了网络状陶瓷增强结构，所制备的复合材料具有较好的强度和韧性，且随着Cr2AlC含量的增加，复合材料的强度也在增加，但断裂韧性逐渐下降。当Cr2AlC的体积分数达到30%时，复合材料的抗弯强度达1417MPa。关键词：复合材料；原位反应；烧结；弯曲行为中图分类号：TB333文献标志码：A文章编号：0454–5648(2013)01–网络出版时间：网络出版地址：FabricationofCr2AlCFe-basedCompositesbyin-situReactionMethodCHENXinhua，ZHAIHongxiang，WANGWenjuan，HUANGZhenying(CenterofMaterialsScienceandEngineering,SchoolofMechanicalandElectronicControlEngineering,BeijingJiaotongUniversity,Beijing100044)Abstract:ACr2AlC-Fecomposite,whichcouldhavepotentialapplicationsinnuclearenergyindustryasengineeringmaterials,wassynthesizedbyanin-situreactionmethod.Thein-situreactionsbetweenCr2AlCandFeatdifferenttemperaturesandratioswereana-lyzedbythermogravimetricanalysis-differentialthermalanalysis,X-raydiffractionandscanningelectronmicroscopy,respectively.TheeffectofsCr2AlCcontentonthebendingbehaviorswasinvestigated.TheresultsshowthatCr2AlCcanin-situreactwithFe,anddecomposetoformchromiumcarbide.Thesynthesizedcompositeexhibitsahigherflexuralstrengthandagreaterfracturetoughnessatroomtemperature.Keywords:basedcomposites;insitureaction;sintering;bendingbehaviors1IntroductionCombinewiththeuniquedesirablepropertiesofasin-glemetalorceramicmaterialandoffsettingeachother'sdeficiencies,compositescanbeusedastheengineeringmaterialsforextremeenvironmentofnuclearenergyin-dustry,miningindustry,chemicalandmetallurgicalin-dustryandsoon.[1–3]ThereinforcingceramicparticulatesincludeAl2O3,TiC,Si3N4,WC,etc..[4–8]Althoughthosetraditionalceramicreinforcementsownhighstrength,theyhavelowfracturetoughness,poorwetting,incon-sistencyoflinearexpansioncoefficientwithiron,andarehardtobemachinedbyusingnormaltools.Recently,Cr2AlCandrelatedcompositeshaveattractedincreasingattention,[9–13]whichbelongtoanewtypeofternarystructuresadvanceceramicssocalledMAXphase.Comparedwithtraditionalceramicreinforcingagents,thesekindsofceramicspossessuniquecrystallaminatedstructureasgraphite.IntheCr2AlCcrystalstructure,theCratomsandCatomsformtwocommonedgesCr6Ctetrahedronwithstrongionicbondaresepa-ratedbyAlatomicplanes,[14]andthelinkbetweenAlatomicplanesandCr6CtetrahedronareweakCr–Alme-tallicbond.[15–16]ThisstructureleadtheCr2AlCphasecombinationalpropertiesofbothmetalsandceramics,suchaslowdensity,highmodulus,easymachinability,goodelectricalandthermalconductivity,excellentther-malshockandhigh-temperatureoxidationresistance,butalsocanreactwithFebythetechniqueofinsitureactionmethod,[17–19]whichisaprocesswhere收稿日期：2012–04–23。修订日期：2012–09–25。基金项目：国家“863”项目(2006AA03Z527)。第一作者：陈新华(1983—)，男，博士研究生。Receiveddate:2012–04–23.Reviseddate:2012–09–25.Firstauthor:CHENXinhua(1983–),male,Ph.D.,Candidate.E-mail:[e-mail]esizedinmetallicmatrixbychemicalreactions,andensuredtheintroductionof第41卷第1期2013年1月硅酸盐学报JOURNALOFTHECHINESECERAMICSOCIETYVol.41，No.1January，2013陈新华等：原位反应法制备Cr2AlC-Fe复合材料·2·第41卷第1期chemicalbondingforceintheinterfaceofthereinforce-mentsandthemetalmatrix,andthehighperformancebondingwillmaketheexternalappliedstresstransferredfromthematrixtothereinforcements.Zhangetal.[20]nosedoutthatthereactionbetweenCuandTi3AlC2formTiCxandCu(Al)above950℃.Ourpreviouswork[21–24]showsthattheincorporationofTi3SiC2orTi3AlC2withCuincreasethestrengthandmodulusaswellaswearresistancewithoutthelossofconductivityandmeettherequirementsofapplicationsinelectricalslidingcontactsinhigh-speedrailway.Infact,similarreactionsalsoexistbetweentheCr2AlCwithFematrix.Hence,thispaperintendstoreportonprocessingandpropertyofFe-basedMetalMatrixComposites(MMCs)usingtheCr2AlC,whichisatypememberoftheMAXphaseceramics,asprecursorintherawmaterial.Byus-ingthisin-situreactionmethod,theCr2AlCceramicpar-ticlesmightdecomposetofinechromiumcarbiderein-forcingagents.Differentfromthetraditionaldirectsyn-thesismethods,thismethodhasseveraladvantages,suchasthebetterlinkbetweenthereinforcingagentswiththematrix,andtheeasierdistributedevenlyofthereinforc-ingagents,andsoon.2ExperimentalReducedironpowders(purity99.5%,size74μm,BeijingChemicalReagentCompany)andCr2AlCpow-ders(purity97%,averagesize5.197μm,thedetailscanbefoundelsewhere[10])aremixedfor10hinplasticcanstoensurehomogeneousreactantmixtures.TheCr2AlCparticlepowderssizemeasurementwasperformedonlaserdiffractionparticlesizeanalyzer(Mastersizer2000,Malvern,Britain).Then,themixedpowderswerehot-pressed(HP)at1300℃under30MPafor30mininflowingargongas.Theflexuralstrengthofthecompo-siteswastestedbythree-pointbendingmethodbyGB/T6569–1986,andthefracturetoughnesswastestedbysingleedgenotchedandthree-pointbendingmethod(SENB).Thefinalsampleswerecutintoblockswithdi-mensionsof3mm4mm36mmforbendingtests,of4mm6mm36mmforSENBtests,thebothtestswereperformedonauniversaltestingmachine(ZWICK,Z005)ataloadingspeedof0.5mm/min.Accordingtothestandardforceanddisplacementfromtheuniversaltestingmachine,thebendingstrengthandfracturetoughnessofthecompo-sitesarecalculatedfromfollowingequations