Al2O3／Cu复合材料制备中的Cu2OAl体系化学反应（稀有金属材料与工程论文）

Al2O3Al2O3 CuCu复合材料制备中的复合材料制备中的Cu2OAlCu2OAl体系化学反应 稀有金体系化学反应 稀有金 属材料与工程论文 属材料与工程论文 第36卷xx在增刊39月稀有金属材料与工程RARE METALMATERIALS ANDENGINEER1NG Vo1 36 Supp1 3SeptemberxxChemical Reaction of CuzO AI System in Preparationof AIzO3 Cn Composite WangW uxiao 一 Xing Jiandong Jin Zhixin 1 xi an JiaotongUniversity Xi an710049 China 2 Xi all Universityof Technology Xi all710048 China AbstractThe reactionbehavior of Cu2O and A1was analyzedby chemicalthermodynamics methods temperature time analysis curves weretested and X ray diffractionwas appliedto examinereacted productsin thespecimens fabricatedfrom Cu2O AI powderpacts The resultsshow that the chemical reaction of Cu20一AI systemincludes threedifferent stagesin the firststage there is a littlereacted products of AlEO3and Cuwhen temperature is lower than910K in thesecond stage chemical reactiondoesn t our in the Cu2O AI systemf rom910K to1103K in thethird stage the reacted products of Cu AI2O3and CuAIO2are formedf rom1103K to1373K Key wordsCu20一AI system chemical reaction mechanism thermal explode AIzO3 Cu positeCLC numberTG146 4Document codeAArticle ID1002 185X xx 3 679 041lntrOductiOn A1203 Cu positesare akind ofmaterial withhigh intensityand highelectric conductivity and ithas widespreadapplication prospect M oreover owing to the enhancementof theA1203particles the materialhas suchbetter abilitiesof anti attrition and anti electric arorrosion At present A1203 Cu positeshave beenused inmicrowave tubesas thestructural materialand areexpected tobe used in manyfacilities includingelectrode headsof resistancewelding shifting switches contact headswhich replacesthe silverand soon Nowadays there aremainly twomethods tomanufacture A1203 Cu positeswhich arepowder metallurgyand internaloxidization America andJapan havedone someexploit andresearch usingthe method of powderspraying inter n al oxidation but thespecif ictechnology isstill merciallyconf identia1 In China investigators ofTianjin Universi够adopt powdermetallurg yintern aloxidationand hotpress means in whichtechnology isplex and the costis highwhile thenatural capabilityof thematerials stillhas somedif ferencesparing with the overseascongener produc The authorsadopt themethodofdirect internal oxidationin Cu and thereinforcement growsup in Cu matrixby nucleation The methodpossess thermodynamicsstability and theinterface ofposite linkswel1 However when CuO and A1are addedto liquidcopper incer tainconditions CuO reactsharply with A1 which willemit ahuge amount of heatinstantly thatcan t betransmitted bysurrounding mediumtimely Therepore it makesthe systemtemperature riserapidly As aresult the surounding gasexpands soshar ply that thermal explosionours 4 Ther mal explosionsmay causeliquid tosplash leading to failure ofinternal oxidationtechnology and evencause theequipment todamage It hasbee arestrictive linkin manufacturingA1203 Cu positeswith internal oxidationtechnology In ordertofind anew systemreplacing the CuO andA1system toavoid orlessen theourrence of therm alexplosions an analysisabout chemical reactionmechanismof Cu20andA1system havebeen caried out and theissue whethertherm alexplosion wouldourinthis systemhas beenresolved byexperimentation 2Experim entalM ethodRaw materialsusedin the experimentare asReceived datexx 10 30 Revised manuscriptreceived datexx 07 08Foundation ItemChinesePostdoctoral ScienceFoundation xx0391005 biographywang wuxiao ph d school ofmaterials science and engineering xi an universityoftechnology xi an710048 p r china tel0086 029 82312557 e mailwangwuxiao 163 cor n稀有金属材料与 l程第36卷fo jjowsthe powderof cu2o with an average diameter of71p m whose purityisn t lower than90 0 the powderof a1with anaverage diameter of71gm whose purityisn t lower than99 5 the powderofcu with anaveragediameterof71p m whose purityisn t lowerthan99 8 the cu2oandai powdersare poundedon thebasis of the balanceequation 3cu20 2al3cu al203 the powdersare mixedand pressedinto prefabricatedblocks withdiameterof14mm andlength of20r amat apressure of15ton indry condition after thetreatment ofdrying andexhaust specimens reactin airat temperatures of1093k 1273k and1373k for30minutes respectively the thermalanalysis curvesof temperature varying with time inreaction arerecorded bya xwt 464balance recordingmeter couplingwithatemperature determining electricdipole pared with the medium temperature if exotherrnihemical reactionsour the sample s temperaturewill beobviously higher than the medium temperature x ray difraction deviceof japanesed max 3c isused foranalyzing the reaction products 3experim entresults andanalysis3 1determination of therm alanalysis curvesfig 1shows thermalanalysis curvesof cu20 a1 specimens reactiontemperaturevaryingwithtimeat1093k 1273k and1373k contrast withfig 1 fig 2which hasbeen reportedin literature 4 shows cuo a1 specimens temperatureanalysiscurves it can be seenin fig 1that there are smallraised inflection points showingup in curve a b andc at883k indicating thatchemical reaction ours in cu20 ai systemand someheat isemitted which made the temperature of thesystem sharplyrise to910k but theheat isn t moreenough because it is transmittedvia surroundingmedium quickly and thus the reactionis verycalm subsequently the temperatureofthesystem continuedto risewith theincrease ofthe temperatureof furnace w henit ishigherthan910k there isno raisedinflectionpointappearing incurve auntil the sample s temperature is equaltothe furnace s which indicatesthat exothermihemical reaction incu2o ai systemtime min fig 1temperature analysiscurves obtained at medium temperatures of1093k a 1273k b and1373k c for cu20 a1 specimens internal oxidation time min fig 2temperature analysiscur v es obtainedatmediu mtemp eraturesof1073k a 1183k b 1203k c and1223k d for cuo a1 specimens fromref 4 doesn t ourwhen temperatureis between910k and1093k in curve b heated infurnace for20minutes the sample s temperature rises to1103k and then itsharp rises to1356k it takesabout1minute for thiscourse w hentemperatureriseto1356k the melting pointofcu themeltingcourse absorbedpart heatofthesystem which madethe temperaturestop rising w iththe timepassing thereactionstops andthe sample s temperaturedrops graduallyto1273k which is approachingand consistentwith thefur nace s temperatureultimately the appearanceof raised peak atl103k incurve bindicate thatthe chemical reaction oursagain incu20一ai systemand muchheat isemitted w henmediumtemperatureis1337k curve cis similarto curv eb raisedpeakexist also while themediumtemperatureincurvec risesmore higher therefore it spendsonly25s for the sample torise from1103k tothe peaktemperature which isless thanthe timespending in增刊3wang wuxiaoet alchemicalreactionofcu20 a1systeminpreparation ofa1203 cu posite 681 curveb in addition in thetesting process a slightreaction soundcanbeheard which indicatesthatthereaction takesplace more sharplywiththeincrease ofthemediumtemperature 3 2x ray diffractionanalysis fig 3shows thex ray diffractionanalysis results ofthe samples obtainedby internaloxidization treatment at medium temperaturesof1093k 1273k and1373k in fig 3a it canbe seenthat at1093k thesample s ponentphases are cue0 a1 cu with6 content anda12o with3 content which indicate that there isa chemical reaction ours incu2o al system but thereaction isn t pleted at1273k as fig 3b shows thesample s ponentare cu20 cuwith27 content a1203with8 content and cua102 which indicatethat aobvious chem icalreactionours incu20一a1system at1373k asfig 3c shows thesample s ponentarecu20 a1203and cua102 which indicatethatthe product ofcu in the chemicalreaction ofcu20一a1system isoxidized intocu20gradually inair c甚宣兰罟 cu20a cu al a1203 l k l c cu2o also3o cua10 1 o l 15 0026 0037 0048 0059 0070 00 20 Fig 3XRD obtainedatmediumtemperaturesof1093K a 1273K b and1373K c for CuzO A1 specimens Inthermal curvesandX ray diffractionanalysis it canbe seenthat in the Cu20一A1system atthe highest temperatureofinternaloxidationsample1356K themelting pointofCuis muchlowerthanthat athighesttemperature1600K in theCuO A1system reportedin literature 4 asFig 2shows Therefore itisbetter toadopt internaloxidation toproduce AlzO3 Cu positesin theCu20一A1system thanintheCuO A1system For theanalysis hereinbefore theCu20 A1system canbe dividedinto threedifferent phases 1 The temperatureof this phase is lowerthan910K there isa littleproduct of A1203and Cuwhile littleheat isemitted The possiblechemicalreaction equations areas followsCu20 1 2 O2 2Cu O 1 2Cu O 4 3 A1 2Cu 2 3 A1203 2 There isan unstablem id product Cu O createdwhen Cu20reacts withoxygen inthe air At thesame timetheunstable Cu O isconsumed quicklyby reactingwithA1as Eq 2shows As aresult the totalreactionequationof this phase isas followCu20 1 2 O2 4 3 A1 2Cu 2 3 A1203AGm 一822973 14 6 62T J mo1 3 2 The temperaturerange ofthisphaseis between910K and1103K and noreactionoursinCu20一A1system 3 The temperaturerange ofthisphaseis between1103K and1373K As the temperature risesto1103K A1can react with Cu20andthereaction equationsare Eq 4as foliows 6Al 4Cu20 302 2A1203 2CuA102 6Cu 4 The chemicalreactioninEq 4consists ofthe followingsteps4A1 302 2A1203 G 一1616100 278 1J mo1 5 Cu20 A1203 2CuA102 Gm 一 22940 8 62J mo1 6 2Al 3Cu2O A12O3 6Cu G 一1283100 151 9J mo1 7 in fig 1 it canbe seenthat thereis raisedpeaks at1103k incu20一a1system indicating thatachemicalreactionoursandahuge amountofheat emitted which isin agreementwith eq 4 the researchresults inliteratures 6 8 indicatethatinthecu o a1system therearetwo kindsof stableter naryoxides whichare cua1204 spine1 and cua102 hexahedron when thetemperatureislowerthan1173k cu20reactwitha1203andthepro duct iscua1204 一口 682 稀有金属材料与工程第36卷but when temperatureisbetween1173k andl473k theproductis cuaio2 which isin withfig 3 w henthetemperaturerisestol373k cu productwill beoxidized intocu20during theexperiment whichisin agreementwiththeresultsofliterature 9 4conclusions thechemicalreaction ofcu2o al systemincludes threedifferent phasesinthefirst phase thereisa littlereactedproductsofa1203andcuwhentemperatureislowerthan 9l0k inthesecond phase chem