高纯多晶铝的动态再结晶

356200412()J.CENT.SOUTHUNIV.(SCIENCEANDTECHNOLOGY)Vol.35No6Dec.2004,,,(中南大学材料科学与工程学院,湖南长沙,410083):将99.992%高纯多晶铝在533~773K时以0.002~2.000s-1的应变速率压缩到其真应变为0.92采用真应力-真应变曲线以及偏光金相和透射电镜研究高纯铝高温塑性变形特征,研究了形变条件对高纯铝动态软化机制的影响研究结果表明:高纯铝的动态软化机制与Zenner-Hollomon参数Z密切相关,当Z较大时,试样仅发生动态回复;Z处于中间值时,发生连续动态再结晶;Z较小时,发生不连续动态再结晶,但真应力-真应变曲线未出现波动:高纯铝;Zenner-Hollomon参数;高温变形;再结晶:TG111.7:A:1672-7207(2004)06-0935-06DynamicRecrystallizationofHighPurityPolycrystallineAluminumJIANGShu-nong,LIUChu-ming,LIHu-izhong,ZHANGXin-ming(SchoolofMaterialsScienceandEngineering,CentralSouthUniversity,Changsha410083,China)Abstract:SpecimensofhighpurityAluminumof99.992%gradewerehotcompressedtoatruestrainof0.92at533773Kandwithstrainratesof0.0022.000s-1.Thedynamicrestorationmechanismswereexam-inedbythetruestress-truestraincurves,polarizedmicroscopyandtransmissionelectronmicroscopy.Theef-fectofparameterZ(Zener-Hollomomparameter)ontherestorationmechanismsofhighpurityaluminumwasinvestigated.TheresultsshowthatonlydynamicrecoveryoccurswhenparameterZishigh;continuousdy-namicrecrystallizationoccurswhenparameterZisintermediate,anddiscontinuousdynamicrecrystallizationtakesplaceifparameterZislow.Butthetruestress-truestraincurvedoesnotaccompanystressoscillationwhendiscontinuousdynamicrecrystallizationoccurs.Keywords:highpurityaluminum;Zenner-Hollomonparameter;hotdeformation;recrystallizationfcc,,,,,,[14],2:,,,[5],,,-,,:2004-05-19:(G1999064908):(1979-),,,,:,,,;:0731-8830257(O);E-mail:[e-mail](99.999%),,,-,,6mm,99.992%,,199.992%0.001%Si,0.0009%Fe,0.0028%Cu,0.0001%Mn,0.001%Mg,0.0006%Cr,0.0002%Ni,0.001%Zn,0.0002%Ti0.0002%Zr()10mm15mm,0.2mmRastegaev[6]Gleeble1500,533~773K,0.002~2.000s-1,0.9275%+20%+5%,,1s++,Poltver-met,,,JEOL100CXII22.1-,0.002~2s-1,-11,,T=533K,-,;,,;,,,/s-1:(a)2.000;(b)0.200;(c)0.020;(d)0.0021不同形变条件下的等温压缩真应力-真应变曲线Fig.1Truestress-truestraincurves936()35,[6]-,2.2ZZenner-HollomanZ:Z=exp[Q/(RT)](1):,s-1;T,K;Q,kJ/mol;RZ,Z-p[7]:Z=Anp(2):An(1)(2):Anp=exp[Q/(RT)](3)(3),,:lnp=n;(4),:lnp(1/T)=Q/(Rn)(5)-,Q=142kJ/molQZ2~40.9299.992%Z:lnZ28(2(a),3(a)),,;20lnZ28(2(b)~2(d),3(b)),,,,[8],lnZlnZ,;lnZ20(3(c)~3(d),4(a)4(b)),,,,,,lnZ-(a)T=533K,lnZ=30.4;(b)T=673K,lnZ=23.8;(c)T=723K,lnZ=22.0;(d)T=773K,lnZ=20.52试样在形变速率为0.200s-1,等温压缩至真应变为0.92时的偏光显微金相组织Fig.2POMmicrographsofspecimensdeformedbycompressionat0.200s-1toatruestrainof0.929376,:(a)T=533K,lnZ=28.1;(b)T=673K,lnZ=21.5;(c)T=723K,lnZ=19.7;(d)T=773K,lnZ=18.23试样在形变速率为0.020s-1,等温压缩至真应变为0.92时的偏光显微金相组织Fig.3POMmicrographsofspecimensdeformedbycompressionat0.020s-1toatruestrainof0.92(a)T=673K,lnZ=19.2;(b)T=723K,lnZ=17.44试样在形变速率为0.002s-1,等温压缩至真应变为0.92时的偏光显微金相组织Fig.4POMmicrographsofspecimensdeformedbycompressionat0.002s-1toatruestrainof0.9250.020s-10.92TEM5(a)3(a)TEM5,,[9]5(b),A,A,5(c),[10],,,938()35(a)T=533K,lnZ=28.1;(b)T=673K,lnZ=21.5;(c)T=723K,lnZ=19.75试样在形变速率为0.020s-1,等温压缩至真应变为0.92时的TEM图片Fig.5TEMmicrographsofspecimensdeformedbycompressionat0.020s-1toatruestrainof0.92,,2.32(99.99%)[11],(99.999%)[12,13]-,-[14,15],H.YAMAGATA99.99%373~853K1.6710-3s-1,613K693K,853K,-[14,15],3:a.1;b.,,;c.,[11],H.YAMAGATA,,[16]:,;,,,,,,,,,,,-[14,15],,:,,,-;,99.992%,,,,,99.992%-2:,,,;,,,,[17],3a.9396,:,b.99.992%Z:lnZ28;20lnZ28;lnZ20c.99.992%,-,-:[1]BELYAYEVSP,LIKHACHEVVA,MYSSHLYAYEVMM,etal.DynamicRecrystallizationofAluminum[J].PhyMetMetall,1981,52(3):143148.[2],,.[J].,1987,(10):3640.LIUShu-yun,ANX-iyong,CUIHua-iling.DynamicRecrystallizationofPureAluminum[J].LightAlloyFabricationTechnology,1987,(10):3640.[3]YAMAGATAH.MultipeakStressOscillationsofFive-nine-purityAlu-minumDuringaHotCompressionTest[J].ScriptaMetallMater,1992,27(2):201203.[4]YAMAGATAH,OHUCHIDAY,SAITON,etal.DynamicRecys-tallizationandDynamicRecoveryof99.99mass%AluminumSingleCrystalHaving[112]Orientation[J].JMaterSciLett,2001,20:19471951.[5]YAMAGATAH,OHUCHIDAY,SAITON,etal.DynamicRecrys-tallizationandDynamicRecoveryof99.99%AluminumSingleCrystalHaving[112]Orientation[J].JMaterSciLett,2001,20:19471951.[6]POIRIERJP.[M].,.:,1989.POIRIERJP.ElevatedTemperatureDeformationofCrystal[M].GUANDe-lin,translates.Dalian:DalianUniversityofTechnologyPress,1989.[7],.A-l2Mg[J].,1999,9(3):510514.LINJun-pin,CHENGJing-wei.DynamicRecrystallizationDuringHotTorsionofA-l2MgAlloy[J].theChineseJournalofNonferrousMet-als,1999,9(3):510514.[8]LINJP,LEITC,ANXY.DynamicRecrystallizationDuringHotCompressioninA-lMgAlloy[J].ScriptaMetallMater,192,26(12):18691874.[9]YAMAGATAH.DynamicRecrystallizationandDynamicRecoveryinPureAluminumat583K[J].ActaMetallMater,1995,43(2):723729.[10],.[M].:,1994.MAOWe-imin,ZHAOXin-bin.RecrystallizationandGrainGrowthofMetals[M].Beijing:MetallurgicalIndustryPress,1994.[11]GOURDETS,MONTHEILLETF.AnExperimentalStudyoftheRe-crystallizationMechanismDuringHotDeformationofAluminum[J].MaterialsScienceandEngineering,2000,A283:274288.[12]YAMAGATEH.DynamicRecrystallizationofSingle-crystallineAlu-minumDuringCompressionTests[J].ScriptaMetallMater,1992,27(9):11571160.[13]YAMAGATAH.MicrostructuralEvolutionofSingle-crystallineAlu-minumDuringMultipeakStressOscillationat623K[J].ScriptaMet-allMater,1992,30(4):4114