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锌合金粉在KOH溶液中析氢行为的研究

陈文汨 , 万新华 , 孙英

腐蚀与防护

采用气雾法制备Zn-In、Zn-Pb、Zn-Bi、Zn-Al合金粉,利用收集气体的办法测定了各种合金粉在KOH溶液中的腐蚀速度,确定了In、Pb、Bi、Al四种元素与Zn分别形成合金的最佳含量.随后研究了In、Bi、Al三种金属元素与Zn形成的四元合金的析氢行为.

关键词: 锌合金粉 , 腐蚀 , 碱锰电池

雾化法制备锌粉技术研究

陈文汨 , 万新华 , 孙英

材料导报

用自行设计的限制式雾化喷嘴为核心的雾化装置,研究了在喷嘴关键结构参数(输液管的直径、喷嘴狭缝尺寸、喷射角等)一定的条件下,雾化压力及熔融温度对液锌的雾化效果的影响。结果表明,当雾化介质为N1,压力为0.40~0.50MPa,液锌温度为650℃时,液锌可以获得较好的雾化效果。通过显微镜观察和电镜扫描,发现制备的锌粉大部分为不规则形状。

关键词: 雾化法 , 限制式喷嘴 , 锌粉

超高效液相色谱-串联四极杆飞行时间质谱和超高效液相色谱-串联三重四极杆质谱用于血浆中苦杏仁苷及其代谢产物野黑苷的定性和定量分析

高萌 , 王跃生 , 魏惠珍 , 欧阳辉 , 何明珍 , 曾恋情 , 申峰云 , 郭强 , 饶毅

色谱 doi:10.3724/SP.J.1123.2014.01021

建立了大鼠灌胃麻杏石甘汤后血浆中苦杏仁苷、野黑苷的定性及定量方法。样品经液液萃取净化处理,定性采用超高效液相色谱-串联四极杆飞行时间质谱仪(UPLC-QTOF-MS / MS),经 Shim-pack XR-ODS Ⅲ色谱柱(75 mm×2.0 mm,1.6μm)分离,定量采用超高效液相色谱-串联三重四极杆质谱仪( UPLC-Q-TRAP-MS),经 Agilent C18色谱柱(50 mm×2.1 mm,1.7μm)分离,电喷雾负离子化( ESI)及 MRM 模式测定,流动相均为乙腈-0.1%( v /v)甲酸水溶液。结果显示苦杏仁苷、野黑苷在相应浓度范围内线性关系良好(相关系数分别为0.9990、0.9970),精密度(RSD)小于9.20%,回收率为82.33%~95.25%,检出限( LOD)约为0.50 ng / mL。本方法快速简便,为血浆样品中苦杏仁苷、野黑苷的定性和定量分析提供良好参考。

关键词: 超高效液相色谱-串联四极杆飞行时间质谱 , 超高效液相色谱-串联三重四极杆质谱 , 苦杏仁苷 , 野黑 , 大鼠血浆

模型化合物吡啶、吡咯氧化规律实验研究

孔德娟 , 周屈兰 , 赵科 , 徐通模 , 惠世恩 , 王学斌

工程热物理学报

选用吡啶和吡咯作为模型化合物,在500~1100℃温度范围内,对其进行单独氧化和混合氧化的产物实验研究.实验结果表明,在恪?的时候,吡啶的三种氮氧化物N2O、NO和NO2的生成率随愕脑黾用飨栽黾阢1的时候,三种氮氧化物的生成率随愕脑黾釉虮浠幻飨浴6杂谶拎ず瓦量珻O和N2O都只在特定的温度区间内600~700℃和600~1000℃生成,而NO和NO2的生成率在超过700℃以后趋于稳定.吡啶的氧化过程对氧量变化比较敏感,而吡咯则不敏感.在混合物中,吡咯是优先氧化的.

关键词: 氧化 , 实验研究 , 模型化合物 , N2O , NOx

ATOMIC FORCE MICROSCOPY OBSERVATION OF MAGNETRON SPUTTERED ALUMINUM-SILICON ALLOY FILMS

金属学报(英文版)

粒裕希停桑谩。疲希遥茫拧。停桑茫遥希茫希校佟。希拢牛遥郑粒裕桑希巍。希啤。停粒牵危牛裕遥希巍。校眨裕裕牛遥牛摹。粒蹋眨停桑危眨停桑蹋桑茫希巍。粒蹋蹋希佟。疲桑蹋停?##2##3##4##5ATOMICFORCEMICROSCOPYOBSERVATIONOFMAGNETRONSPUTTEREDALUMINUM-SILICONALLOYFILMSJ.W.Wu,J.H.FangandZ.H.Lu(NationalLaboratoryofMoleculeandBiomoleculeElectronics,SoutheastUniversity,Nanjing210096,ChinaManuscriptreceived27October1995)Abstrcat:Twodifferentsurfacemorphologycharacteristicsofmagnetronsputteredaluminumsilicon(Al-Si)alloyfilmsdepositedat0and200℃wereobservedbyatomicforcemicroscopy(AFM).Oneisirregularlyshapedgrainsputtogtheronaplane.TheotherisirregularlyshapedgrainsPiledupinspace.Nanometer-sizedparticleswithheightsfrom1.6to2.9nmwerefirstobserved.Onthebasisoftheseobservationsthegrowthmechanismofmagnetronsputteredfilmsisdiscussed.Keywords:magnetronsputtering,Al-Sialloy,surfacemorphology,atomicforcemicroscopy,filmgrowthmechanism1.IntroductionTheuseofaluminumalloys[1,2],inparticularAl-Si,isacommonfeatureinmanysinglelevelandmultilevelinterconnectionschemesadoptedinthemanufactureofmicroelectronicdevicesbecauseofseveraldesirableproperties.TheAl-Sigrainmorphology(size.geometryanddistributionofgrainsisassociatedwithstepcoverage[3],electromigration[4]andinterconnectsresistivity[5]etc..Thus,characterizationofAl-Sialloysurfacemorphologyisveryimportant,especiallywhenintegratedintensityincreasesandlinewidthsof0.3to0.5μmbecomecommon.Inthepasttwentyyears,theAl-Sialloysurfacemorphologywhichaffectsthereliabilityofmicroelectronicdeviceshasbeenwidelyinvestigatedbyscanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM)etc.[5-7].However,SEMandTEMhavetheirlimitationorinconvenience,forexample,theverticalresolutionofSEMisnothighandTEMneedscomplexsamplepreparation.Recently,anewgrainboundaryetchingmethodwasproposed ̄[8]whichalsoneedstroublesomechemicaletching.Atomicforcemicroscopy(AFM),sinceitsemerging,hasbecomemoreandmoreusefulinphysics,chemistry,materialsscienceandsurfacescience,becauseofitshighresolution,easeofsamplepreparationandrealsurfacetopography.Recently,discussion[9,10]waspresentedonhowAFMwillplayaroleinsemiconductorindustry.Asaresponsetothisdiscussion,weusedAFMtoinvestigateAl-SialloysurfacemorphologyandhaveobtainedsomeresultswhichcannotberevealedbySEMorTEM.ThisindicatesthatAFMisagoodcharacterizationtoolinsemiconductorindustry.2.SamplePreparationInourexperiments,aluminumwith30ppmsiliconwassputteredonsiliconsubstrateinbatchdepositionmodeAllthreefilmswiththicknessof1.6μmweredepositedusinganargonsputteringpressureof4.2×10 ̄-3Pa.TheotherdepositionparametersaredescribedinTable1.Thesubstratewascleanedusingstandardpremetallizationcleaningtechniquespriortofilmdeposition.3.ExperimentalResultsandDiscussionTheAFMmeasurementswereperformedonacommercialsystem(NanoscopeIII,DigitalInstruments,SantaBarbara).Thetipismadeofmicrofabricatedsiliconnitride(Si_3N_4)Itisattachedtoa200μmcantileverwithaforceconstantofabout0.12N/m.Beforethesurfaceofsamplewasexamined.agoodtipwithananometer-sizedprotrusionatitsendwasselectedbeforehand,whichcanbeobtainedbyimagingtheatomicstructureofmicasubstrateandagoldgrid.AtypicaloperatingforcebetweenthetipandAl-Sisamplesurfaceisoftheorderof10 ̄-8Nandallimagesweretakenatroomtemperatureinair.AtypicaltopographicviewoftheAl-SifilmsisshowninFig.1(allimagescansizeis5by5μma,bandcarerespectivelyforsample1,2,and3).FromFig.la,itcanbeseenthatirregularlyshapedgrainstiltinginvaryingdegreespileupinspace,andgroovesamongtheirregularlyshapedgrainsaredifficulttodecideatacertainarea(wedefineitascharacteristicA).Toourknowledge,onreportsonthesurfacemorphologyhavebeenpresentedbefore.InFig1b,however,irregularlyshapedgrainsassembleonaPlaneandgroovesamongtheirregularlyshapedgrainsareeasytodecide(wedefineitascharacteristicB),whichisinagreementwithmanypreviousreports[5-7].InFig.1c,bothcharacteristicA(arrowA)andcharacteristicB(arrowB)wereobserved.IndoingAFMexperiments,weselectedfivedifferentscanareastobeimagedforeachsampleandfoundthatallimagesofeachsamplearerespectivelysimilartoFig.1a,bandc.Also,wenotedthatthesurfaceofinFig.1a.WethinkthatdepositionparameterswillinfluenceAl-Sisurfacemorphology,andthetiltedgrainsmaybesusceptibletomicrocracking.Byreducingthescansizeareato2by2μm(Fig.2aandb).Weobtainedmanyidenticalresultsasdescribedabove,suchasirregularlyshapedgrainsetc.Forthefirsttime,wefoundnanometersizedparticlesonirregularlyshapedgrainsurfacewhichcannotberevealedbySEMbecausethediameterofthesenanoparticlesisabout10nmandtheheightofthesenanoparticlesisintherangeof1.6to2.9nm.Inimaging,wenotedthatrotatingthescandirectionandchangingthescanfrequencydidnotaffectthestructureofthesegrainsasshowninFig.2aandb,rulingoutthepossibilitythatscanninginfluencedtheshapeoftheseparticlesorcausedsomesimilarimagingartifacts.Also,wenotedthatthenanoparticleswerenotobservedontheslopesofthegrooves(Fig.2aandb).Thisphenomenoncanbeexplainedasfollows:thepotentialenergyattheslopeislargerthanthatelsewhere,sotheparticlesseemmorelikelytobedepositedontheseareaswithlowerpotentialenergy.Fig.2c,scansize250by250nm,isazoomtopographicimage(whiteoutlineinb).Itshowsunevendistributionofthenanoparticles.Andtheheightdifferenceofthenanoparticlesindicatesdifferentgrowingspeed.Wethinkbasedonthemorphologyofnanoparticles,thattheheightdifferenceandunevendistributionofthesenanoparticlesshowdifferentgrowingadvantageandindicatethatatomshaveenoughenergytomovetoasuitablegrowingspot.Theenergymaybefromthefollowingsources:surfacetemperaturefluctuation,stressdifferenceorcollisionbetweenhighspeedsputteredatoms.Thesenanoparticlesgoongrowingandformmanyirregularlyshapedgrains.AndtheseirregularlyshapedgrainsfurtherconnecteachotheraccordingtocharacteristicAorB,finallyformingtheAl-Sisurfacemorphology.4.ConclusionWecandrawthefollowingconclusionsfromtheabove.First,theexperimentalresultsshowedthatAFMisapowerfultooltoinvestigatethedetailsofAl-Sisurfacemorphologywhichcangreatlyenrichourknowledgeofthefilmgrowthmechanism.Second,depositionconditionsplayanimportantroleindeterminingtheAl-Sisurfacemorphology.Third,thetwoAl-Sisurfacemorphologycharacteristicsarethatirregularlyshapedgrainsassembleonaplaneandirregularlyshapedgrainstiltinginvaryingdegreespileupinspace.Fourth,forthefirsttime,nanoparticleswereobservedonirregularlyshapedgrainsurfacewhichsuggestedthatthefilmgrowthmechanismwasbyinhomogeneousnucleation.Acknowledgements-BeneficialdiscussionswereheldwithDr.ZhenandMr.Zhu.ThisworkwaspartiallysupportedbytheNationalNaturalScienceFoundationofChina.RFFERENCES||1D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)127.2D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)131.3D.pramanikandA.N.Saxena,SolidStateTechnol.33(1990)73.4S.S.IyerandC.Y.Worg,J.Appl.phys.57(1985)4594.5J.F.Smith,SolidStateTechnol.27(1984)135.6D.GerthandD.Katzer,ThinSolidFilm208(1992)67.7R.J.WilsonandB.L.Weiss,ThinSolidFilm207(1991)291.8E.G.Solley,J.H.Linn,R.W.BelcherandM.G.Shlepr,SolidStateTechnol33(1990)409I.SmithandRHowland,SolidStateTechnol.33(1990)53.10L.Peters,SemiconductorInternational16(1993)62.##61D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)127.2D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)131.3D.pramanikandA.N.Saxena,SolidStateTechnol.33(1990)73.4S.S.IyerandC.Y.Worg,J.Appl.phys.57(1985)4594.5J.F.Smith,SolidStateTechnol.27(1984)135.6D.GerthandD.Katzer,ThinSolidFilm208(1992)67.7R.J.WilsonandB.L.Weiss,ThinSolidFilm207(1991)291.8E.G.Solley,J.H.Linn,R.W.BelcherandM.G.Shlepr,SolidStateTechnol33(1990)409I.SmithandRHowland,SolidStateTechnol.33(1990)53.10L.Peters,SemiconductorInternational16(1993)62.##A##BATOMIC FORCE MICROSCOPY OBSERVATION OF MAGNETRON SPUTTERED ALUMINUM-SILICON ALLOY FILMS$$$$J.W.Wu,J.H. Fang and Z.H.Lu (National Laboratory of Molecule and Biomolecule Electronics,Southeast University,Nanjing 210096, China Manuscript received 27 October 1995)Abstrcat:Two different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.

关键词: :magnetron sputtering , null , null , null , null

INVESTIGATION OF HYDROGEN INDUCED DUCTILE BRITTLE TRANSITION IN 7175 ALUMINUM ALLOY

金属学报(英文版)

桑危郑牛裕桑牵粒裕桑希巍。希啤。龋伲模遥希牵牛巍。桑危模眨茫牛摹。模眨茫裕桑蹋拧。拢遥桑裕裕蹋拧。裕遥粒危桑裕桑希巍。桑巍。罚保罚怠。粒蹋眨停桑危眨汀。粒蹋蹋希?##2##3##4##5INVESTIGATIONOFHYDROGENINDUCEDDUCTILEBRITTLETRANSITIONIN7175ALUMINUMALLOY$R.G.Seng:B.JZhong,MG.ZengandP.Geng(DepartmentofMaterialsScierce,ScienceCollege,NorthearsternUniveisity,Shenyang110006,ChinaMaruscriptreceived4September1995inrevisedform20April1996)Abstrac:Effectsofhydrogenonthemechanicalpropertiesofdifferentlyaged7175aluminumalloyswereinvestigatedbyusingcathodicH-permeation,slowstrainratetensionandsoon.Theresultsindicatethatboththeyieldstressandthepercentagereductionofareadecreasewithincreasinghydrogenchargingtime,andthedegreeofreductiondecreasesasagingtimeincreasesforthesamehydrogenchargingtime.Keywords:hydrogeninducedductile-brittletransition,7175aluminumalloy,mechanicalproperty,cathodicH-permeation1.IntroductionForalongtimehydrogenembrittlementproblemwasthoughttobeabsentinhighstrengthaluminiumalloybecausethesolutiondegreeofhydrogeninaluminumatcommontemperatureandpressureisverysmall.However,hydrogenembrittlementphenomenonwasfoundinaluminumalloyduringtheinvestigationofstresscorrosionandcorrosionfatigue[1-5].Therehavebeenonlyafewreportsofhydrogeninducedsofteningandhardening.Inthispaper,theeffectsofhydrogenonmechanicalpropertiesof7175aluminumalloywereinvestigatedbyusingcathodicalchargingwithhydrogenandslowtensiontests.2.ExperimentalProcedureTheexperimentalmaterialwas7175aluminumalloyforgingintheformofa43mminthicknessandwithcomposition(wt%).5.41Zn,2.54Mg.1.49Cu,0.22Cr,0.1Mn.0.1Ti,0.16Fe.0.11Si,balancedbyA1.Alloyplateof1.5mminthicknesswasobtainedbyhot(465℃)andtoldrollingto83%reductioninthickness.Thelongaxisofhydrogenchargedspecimensisalongtherollingdirection.Allspecimensweresolidsolutionedat480℃for70min,followedtyimmediatequenchinginwaterandthenagedat140℃for6h(A),16h(B)and98h(C).Thetreatmentof6hiscorrespondingtotheunderagedstate.16hthefirstpeak-agedstateand98hthesecondpeak-agedstate.Thespecimenswerepolishedsuccessivelyusingemerypaperbeforehydrogencharging.Thetensilespecimenswerecathodicallychargedina2NH_2SO_4solutionwithasmallamountofAs_2O_3forpromotinghydrogenabsorption,andwithacurrentdensityof20±1mA/cm ̄2atroomtemperature.ThehydrogencontentanalysiswascarriedoutonanLT-1Amodelionmassmicroprobeafterthesputteringdepthreached8nm.Theioncurrentsofhydrogenandaluminuminvariousagedstateswererecordedunderthesamecondition.ThetensiletestswereperformedonanAG-10TAmodeltestmachinewhichwascontrolledbycomputer.3.ExperimentalResultsTheratioofioncurrentstrengthofhydrogentoaluminumisrelatedtohydrogenconcentrationinhydrogenchargedspecimen.TheresultswereshowninTable1Thehydrogencontentincreaseswiththeincreaseincharingtime.Ofthethreeagedstates,theunderagedspecimenhasthehighesthydrogencontent.Theratioofyieldstrengthofhydrogenchargedandunchargedspecimenschangeswithhydrogenchargingtime,asshowninFig.1Itcanbeseenthattheyieldstrengthofhydrogenchargedspecimendecreasewithincreasinghydrogenchargingtime.Atthesamechargingtime,theyieldstressdecreasestheleastinthesecondpeak-agedstate,anddecreasesthemostintheunderagedstate.Itindicatesthattheunderagedspecimenismostsensitivetohydrogeninducedsoftening,whichisconsistentwiththeresultsofanotherhighstrengthaluminumalloy[6].TherelativechangesoftheradioofreductionofareawithhydrogenchargingtimearesummarizedinFig.2,whereΨ ̄0andΨ ̄Harethepercentagereductionofareaofthesamplewithoutandwithhydrogenchargingrespectively.Theradioofreductionofareareduceswhenhydrogenchargingtimeincreases,andthedecreasingdegreeofreductionofareaincreaseswithincreasingagingtime,ie,,theunderagedstateisthemostsensitivetohydrogenembrittlement.4.DiscussionItisknownfromtheresultsabovethatcathodicalchargingwithhydrogenleadstotheobviousdecreaseinthetensilestrengthandplasticityThisisbecausealargeamountofsolidsolutionhydrogenentersthespecimenintheprocessofhydrogenchargingSolidsolutionhydrogenisliabletoenterthecentreofdislocationundertheactionofdislocationtrap,henceraisingthemovabilityofdislocation.Thereforethedislocationsinhydrogenchargedspecimenmoveeasierthaninunchargedspecimen.soresultinginthereductionofyieldstrength[7].Whendislocationstartstomove,thecrystallatticeresistance(P-Nforce)whichitmustovercomeisgivenby:whereμismodulusofshear,visPoissonratio,aisspanofslipplane,bisatomspanofslipdirection.Moreover.theotherresistanceofdislocationmotionmayarisefromtheelasticinteractionofdislocation,theactionwithtreedislocationandetc.,itcanbeexpressedasfollows:whereαisconstant,XisdislocationspanSotheresistanceofdislocationmotioncanbewrittenasfollows:Becausehydrogenatomsreducetheatombondingstrengthafterhydrogencharging,shearmodulusμdecreasesandresultsinthereductionoff,therebytheyieldstressdecreases.Asthecentreofdislocationistheseriousdistortionzoneoflattice.thestresscanberelaxedafterhydrogenatomstuffing,andthesystemenergydecreases.Thusthecentreofdislocationisastrongtrapofhydrogen[8].Therefore,amovabledislocationcaptureshydrogenandmigratestograinboundaries.phaseboundariesorsurfaceofthespecimen,promotingthecrackiesformationandgrowth,thuscausingthelossofplasticity.Sincethelocalenrichmentofhydrogenisrealizedbydislocationtransporting(inthestageofdeformation),thelargerthereductionofyieldstress.theearlierarehydrogenatomstransportedtotheplaceofenrichment.Inaddition,thedamageofatombondingstrengthinducedbyhydrogenmakesthefracturestressdecrease[9]:whereCHishydrogenconcentration.σ_thisfracturestrengthbeforehydrogenchargingandisfracturestrengthafterhydrogencharging.Eq.(4)showsthatthematerialsmaybefracturedatalowerstraini.e.,brittlefractureoccurs.5.Conclusions(1)Hydrogencontentofdifferentlyagedspecimensincreaseswithincreasinghydrogenchargingtimethecapabilityofthealloytoabsorbhydrogeninunderagedstateisthestrongest.(2)Theyieldstressaswellasthepercentagereductionofareaof7175aluminumalloydecreaseashydrogenchargingtimeincreasesundervariousagedstates.(3)Underagedstateismostsensitivetohydrogeninducedsofteningandhardening.(4)Anexplanationwasofferedforthephenomenonofhydrogeninducedsofteninginthestageofdeformation,andhardeninginthestageoffracture.REFERENCES||1G.KKock,Corrosion35(1979)73.2M.K.TsengandH.LMarcus,Scr.Metall.15(1981)427.3PSFao.M.GaoandR.P.Wei,Scr.Metall.19(1985)265.4R.G.SongandM.K.TsengJ.NortheasternUniversity15(1994)5(inChinese).5R.K.Viswanadham,T.S.sunandJ.A.S.Green,Metall.Trans.11A(1980)85.6J.Liu,M.KTsengandB.R.Liu.NonferrousMiningandMetallrgy5(1989)33(inChinese).7LChen,WXChen,ZHLiuandZ.Q.Hu,InFrocofthe1stNationalConfonAl-LiAlloys(Sheryang.China,1991)p.328(inChinese).8Z.HLiuL.ChenW.XChenY.X.ShaoandZ.Q.Hu,InProc.ofthe1stNationalConfonAl-LiAlloys(Shenyang,China,1991)p.334(inChinese).9R.A.OrianiandF.H.Josephic,ActaMetall.22(1974)1065.##61G.KKock,Corrosion35(1979)73.2M.K.TsengandH.LMarcus,Scr.Metall.15(1981)427.3PSFao.M.GaoandR.P.Wei,Scr.Metall.19(1985)265.4R.G.SongandM.K.TsengJ.NortheasternUniversity15(1994)5(inChinese).5R.K.Viswanadham,T.S.sunandJ.A.S.Green,Metall.Trans.11A(1980)85.6J.Liu,M.KTsengandB.R.Liu.NonferrousMiningandMetallrgy5(1989)33(inChinese).7LChen,WXChen,ZHLiuandZ.Q.Hu,InFrocofthe1stNationalConfonAl-LiAlloys(Sheryang.China,1991)p.328(inChinese).8Z.HLiuL.ChenW.XChenY.X.ShaoandZ.Q.Hu,InProc.ofthe1stNationalConfonAl-LiAlloys(Shenyang,China,1991)p.334(inChinese).9R.A.OrianiandF.H.Josephic,ActaMetall.22(1974)1065.##A##BINVESTIGATION OF HYDROGEN INDUCED DUCTILE BRITTLE TRANSITION IN 7175 ALUMINUM ALLOY$$$$R.G.Seng: B.J Zhong, MG. Zeng and P. Geng(Department of Materials Scierce, Science College,Northearstern Univeisity, Shenyang 110006, China Maruscript received 4 September 1995 in revised form 20 April 1996)Abstrac:Effects of hydrogen on the mechanical properties of differently aged 7175 aluminum alloys were investigated by using cathodic H-permeation, slow strain rate tension and so on. The results indicate that both the yield stress and the percentage reduction of area decrease with increasing hydrogen charging time, and the degree of reduction decreases as aging time increases for the same hydrogen charging time.

关键词: :hydrogen induced ductile-brittle transition , null , null , null

CRYSTALLIZATION OF Fe_(38)Ni_(39)Si_(10)B_(13) METALLIC GLASS UNDER HELIUM ION IRRADIATION

金属学报(英文版)

茫遥伲裕粒蹋蹋桑冢粒裕桑希巍。希啤。疲錩(38)Ni_(39)Si_(10)B_(13) METALLIC GLASS UNDER HELIUM ION IRRADIATION##2##3##4##5CRYSTALLIZATIONOFFe_(38)Ni_(39)Si_(10)B_(13)METALLICGLASSUNDERHELIUMIONIRRADIATION$YANGQifa(ChinaInstituteofAtomicEnergy,Beijing)ZHANGGuoguang;SHENWanshui(UniversityofScienceandTechnologyBeijing)Manuscriptreceived20February1995ThecrystallizationfeaturesofFe38Hi39Si10B13metallicglassunder100keVand6μA/cm2heliumionirradiationwithdifferentdosesarereported.ItisfoundthattheFe38Ni39Si10B13metallicglasscrystallizedundertheheliumionirradiationatthetemperaturelowerthantheordinarythermalcrystallizationtemperature.ThepreferentialprecipitationphaseisFeSi,andfollowedbytheeutecticphaseα-Fe.Thecriticaldosefortheformationofheliumbubblesinthematerialisaround5x10 ̄16/cm2.Thesensitivityofcrystallizationduetothetemperaturerisingunderheliumionirradiationandthemechanismofthesequenceofprecipitatedphasearebrieflydiscussed.Keywords:Fe38Ni39Si10B13,metallicglass,crystallization,helium,ionirradiationTheblisteringorflakingoffirstwallmaterialsinducedbyheliumionbombardment,whichisrelevanttothefirstwallsurfaceerosionandplasmacontamination,isacriticalproblemtobeconsideredinfusionengineering.Becauseofthefavourablyphysical,chemicalandotherproperties,especially,thebetterresistanceofblistering,metallicglassesareexpectedtobeapromisingcandidatematerialforthefirstwall.TyagiandNanderkarstudiedsystematicallytheblisteringphenomenaofsomemetallicglassmaterialsunderheliumionandprotonbombardmentwithvariousionenergy,ioncurrentdensityanddose,andfoundthecriticaldoseforblisteringofthesematerials[1-3].However,itisverysuspiciousthatmetallicglasseswillcrystallizeunderheliumionirradiationtolosetheiramorphouscharacter,whichwilldeterioratetheirproperties.GusevaandGordeevareportedthatFe40Ni40B20metallicglassbombardedbyheliumionwithenergyof40keVandionbeamcurrentdensitiesof5-40μA/cm2partiallycrystallizedbelowitsordinarythermalcrystallizationtemperature[4].ByusingXRDexamination,itwasfoundthatα-FeandM3B,M2BandMBwereprecipitated(whereM=FeandNi)underheliumionbombardmentwith5μA/cm2and100μA/cm2ioncurrentdensitiesrespectively.Nevertheless,TyagiandNanderkarfoundthatsomemetallicglassescrystallizedandsomedidnotundersameirradiatedparameters[1-3].Consequently,itisnecessarytoinvestigatetheirradiation-assisted-crystallizationfeatureofmetallicglassesbyheliumionirradiationfortheirapplicationinfusionengineering.Inpresentexperiment,thecrystallizationfeatureofFe38Ni39Si10B13metallicglassunderheliumionirradiationwithenergy100keVandvariousdosesintherangeof5×1016/cm2to1×1018/cm2,andthedistributionofheliumbubblesinmaterialaremeasuredbyusingtransmissionelectronmicroscope(TEM)andX-raydiffraction(XRD).1.ExperimentalApproachTheas-receivedFe-Ni-Si-Bmetallicglassribbonswith10mminwidthand0.2mminthicknessweresuppliedbyBeijingInstituteofMetallurgy.Thenominalcomposition(wt%)ofthematerialisNi47.37,Fe43.91,Si5.81andB2.91fromthechemicalanalysisandthecalculatedconstituentisFe38Ni39Si10B13.TheX-raydiffractogramofas-receivedmaterialdemonstratedthattheas-receivedmaterialhasagoodamoophouscharacter.Thetheimalcrystallizationprocessoftheas-receivedmaterialwastestedbydifferentialthermalanalysis(DTA).Theordinarythermalcrystallizationtemperaturewasdeterminedtobeabout490℃.Rectangularsampleswithanareaof1×2cmanddiscsampleswith3mmindiameterwereemployedrespectivelyforXRDandTEMexperiments.ThesamplesforXRDweremechanicallypolishedtomirrorsurfaee.Ontheotherhand,formakingTEMsamples,thepiecescutfromtheribbonwerethinnedto30μmthicknessfirst,thenpunchedout3mmdiscs,electrothinnedinamixedsolutionof10%perchloricacidand90%ethanolandfinally,thediscswereionmilledtoextendthethinarea.HeliumionirradiationofsampleswascarriedoutonTS51-200/ZKionimplanterinChinaInstituteofAtomicEnergy.ThesampleswerefixedonacopperholderwhichwascooledbyF-113coolant.Thevacuumintargetwasbetterthan3×10-3Paandthescanningareaofionbeamwasabout3×7cm.Thetemperatureridingofthesamplescausedbyionbeambombardmentwasmeasuredbythermalcouple.Undertheirradiationparametersofionbeamenergy100keVandionbeamcurrentdensity6μA/cm2,thetemperaturerisingofsampleswaslowerthan200℃.Theiondosesofimplantedsampleswerechosenfrom5×10 ̄16/cm2to1×10 ̄18/cm2inpresentexperiment.AJEOL-100CXTEMoperatedat100kVwasused.Thecalculatedmeanprojectrangeandrangestragghngofheliumionwithenergy100keVinthematerialwere306.9nmand85.5nmrespectively,whichwassimulatedbycodeTRIM86.2.Results2.1CrystallizationunderionirradiationTheselectedareadiffraction(SAD)patternsofun-irradiatedandirradiatedsamplesareshowninFig.l.Fortheun-irradiatedsample,thepatterniscomposedoftwoconcentricringswhichexhibitatypicalamorphousdiffractionfeature(Fig.la).Ontheotherhand,forirradiatedsamples,agroupofnewconcentricringsappearsonthebaseofamorphousdiffractionrings,whichmeanstheoccurrenceofpartialcrystallizationandtheformationofsomenewprecipitationphasesinoriginalamorphousmaterialsbyionirradiation.Withtheincreaseofiondose,theinitialamorpohousdiffractionringsbecomefainterandtheintensitiesofdiffractionringsprodueedbyprecipitatesdevelopehigher.Itisexpectedthatthecrystallizationinsamplesincreaseswiththeincreaseiniondose.Moreover,iftheiondoseislowerthan5×10 ̄17/cm2,thepatternsshowtypicalpolycrystallinediffractionfeaturewithrandomorientationandveryfinegrains(Figs.lbandlc),butfor1×10 ̄18/cm2iondose,somebrightspotsarise(Fig.ld),thismeansthatsomerelativelargegrainsformedinsampleunderirradiation.FromtheX-raydiffractogramofthesampleirradiatedbyheliumiontodoseof5×10 ̄17/cm2,thediffractionpoaksarestillamorpohousfeatureandnonewpeaks.Itispredictedthatthecrystallizationonlyoccursintheprojectedrangeofions.2.2AnalysisofprecipitationphaseFromindexingofdiffractionringsinFig.lbandFig.lc,theprecipitatephaseisanfcccrystallinestructure.InFig.ld,anadditionalbccphaseisfound(ring3,ring5andring8).Thecalculatedlatticeparametersforprecipitatephasesundervariousiondosesareasfollows:5×1016/cm2a=0.412nm(fcc)l×1017/cm2a=0.42lnm(fcc)5×1017/cm2a=0.428nm(fcc)l×1018/cm2a=0.478nm(fcc)a=0.292nm(bcc)UsingASTMindex,itisidentifiedthatthebccphaseisα-Fe(a=0.2866nm).Todeterminethefccprecipitatephase,weinspectedallcompoundswithfcccrystallinestructurecomposedofelementsFe,Ni,SiandB,foundthatthreecompoundsFeSi(a=0.446nm),FeNi3(a=0.353nm)andFe3Si(a=0.564nm),butthemostfavourablecompoundwasFeSi.Therefore,itisassumedthatthepreferentialprecipitatephaseisFeSi,andisfollowedbytheeutectcphaseα-Feundertheheliumionirradiation.2.3HeliumbubbledistributionThemorphologiesofheliumbubblesformedbyagglomerationofimplantedheliumionsareshowninFig.2.Thesmallblackdotspresentbubblesunderbrightfieldwiththeunderfocusingoperation.FromFig.2,itisrevealedthatbubbleslowerthedensity,butinflateinthedimensionwiththeincreaseiniondose.Moreover,underthehigherdosethebubblesjoinedtogether.Fig.3plotsthechangesofdensitiesanddiametersofbubbleswiththeiondose.ItisevidentthatthecriticaldosetoformbubblesinFe38Ni39Si10B13islowerthan5×1016/cm2,whichisslightdifferentfrom1×1017/cm2reportedbyTyagi[1].3.DiscussionAstheresultsreportedbyGusevaandGordeeva[4],theheliumirradiationcantrulybringonthepartialcrystallizationinmetallicglassFe38Ni39Si10B13belowitsordinarythermalcrystallizationtemperature.GusevaandGordeevaconfirmedthattheprecipitatesinFe40Ni40B20wasα-Fephaseunderheliumionirradiationof40keVenergyand5μA/cm2currentdensity,inwhichthetemperaturerisingofthesampleswaslowerthan200℃.Howerve,inpresentexperiment,thoughα-Fephaseisdetermined,notraceofM3B,M2BandMBprecipitatephaseisobserved,whichwasreportedbyaboveauthorsunderirradiationwithenergyof40keVandioncurrentdensityof30μA/cm2.Inaddition,theprecipitationprocessinpresentexperimentissomewhatdifferentfromtheprecipitationprocessreportedbyaboveauthors,thepreferentialprecipitationphaseisFeSi,andfollowedbytheeutecticphaseα-Fe.CrystallizationofamorphousFe40Ni40B20wasnotobservedbyTyagi,whichwasthesamematerialasthatusedbyGusevaandGordeeva,undertheirradiationwith100keVionenergyand30μA/cm2ioncurrentdensity[3].Itmayrelatetothetemperaturerisingofsamplesorsomethingelse.Accordingtothecomparisonandanalysis,itmaybeconcludedthatthecrystallizationofmetallicglassesisverysensitivetothetemperaturerisinginsamplescausedbyionbeamirradiation.ThereasonofthepreferentialphasetobeFeSiandfollowedα-Femaybethatinanamorphousmaterial,themetalloidelementsshouldkeepatthetotalcontentsabove20at%,otherwisesomeelementsorcompoundswillprecipitatetoremainthebalanceofchemicalcomposition.Therefore,astheprecipitationofFeSianddeclineofSicontentsinasample,FeandNimayprecipitateasaneutecticphaseaccordingtoaboveidea.Inthisexperiment,Feprecipitatedfirstly.ThedifferenceoflatticeparametersbetweenexperimentaldataandASTMstandarddatamayresultsintheexistencesofNiandBetcandincompletecrystallizationinsample.Thegeneralviewpointforirradiation-assisted-crystallizationofmetallicglassbelowtheirthermalcrystallizationtemperatureisthedisplacementdamagesinducedbycollosion-cascadebetweenincidentionsandtargetatoms.Thedisplacementdamagesprovidethenucleatingcentresandtheirradiation-assistedmigrationincreasesthecrystallizeddrivingforce,butnodirectrelationshipbetweenheliumandcrystallization.Thegrowthofagrainiscloselyattributedtothediffusionofneighbouringatomstothegrowingnucleus,whichisreliedonthetemperatureextremely,accordingly,thecrystallizationofmetallicglassisverysensitivetothetemperaturerisingfromionbeambombardmentinanirradiatedsample.4.Summary(l)TheFe38Ni39Si10B13metallicglasswillcrystallizebelowitsordinarythermalcrystallizationtemperatureunderheliumionirradiationwith100keVenergyand6μA/cm2ionbeamcurrentdensity.(2)ThepreferentialprecipitationphaseofthemetallicglassisFeSi,andfollowedbyaneutecticphaseα-Fe.(3)Thecriticaldoseformingheliumbubblesinthemetallicglassisabout5×1016/cm2,whichisslightlylowerthanthedosereportedbyTyagi.(4)Theirradiation-assisted-crystallizaofametallicglassesisverysensitivetothetemperaturerisingcausedbyionbeambombardmentinanirradiatedsample.Acknowledgements─TheauthorswouldliketothankthecolleaguesofIonImplantationGroupinChinaInstituteof.AtomicEnergy.forhelpinginsampleirradiation,alsotoProfe

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