7050铝合金半连续铸锭在DSC分析过程中组织的变化_高凤华

第7卷第3期材料与冶金学报Vol7No3:2007-11-09.:(1981),,,,E-mai:[e-mail].(1952),,,,2008年9月JournalofMaterialsandMetallurgySept.20087050DSC高凤华1,李念奎2,田妮1,赵刚1(1.,110004;2.,150060):DSC(differentialscanningcalorimetry),7050200mmDSC.:7050200mm,477;DSC20/min,,Al2CuMg(S),S490;DSC,.:7050;;DSC;;:TG146.21:A:1671-6620(2008)03-0211-04Microstructuralevolutionofa7050semicontinuouscastingingotduringDSCanalysisprocessGAOFeng-hua1,LINian-kui2,TIANNi1,ZHAOGang1(1.KeyLaboratoryforAnisotropyandTextureofMaterials(MinistryofEducation),NortheasternUniversity,Shenyang110004,China;2.NortheastLightAlloyCo.,Ltd.,Harbin150060,China)Abstract:Theevolutionofthenonequilibriumsolidifiedeutecticof200mmsemicontinuouscastingingotof7050aluminumalloyduringDSCanalysishasbeenstudiedbydifferentialscanningcalorimetry(DSC),opticalmicroscopy(OM)andscanningelectronmicroscopywithenergydispersiveX-rayspectroscopy(SEM-EDS).Theresultsshowthatonlyonekindofnonequilibriumsolidifiedeutecticpresentsinthesemicontinuouscastingingotof7050aluminumalloy,whoseinitialmeltingtemperatureis477.Whentheheatingrateisbelow20/min,thenonequilibriumsolidifiedeutectictransformstoAl2CuMg(Sphase)theinitialmeltingtemperatureofequilibriumSphasebeing490.ItissuggestedthattransformationshouldbeconsideredduringtheheatingprocesswhenanonequilibriumsolidifiedproductisinvestigatedbyDSCanalysis.Keywords:7050aluminumalloy;semicontinuouscastingingot;DSCanalysis;eutectic;overheatingtemperature7050[1],,.Zn,Mg,Cu,[2,3],[4],,[5~7].,.DSC(differentialscanningcalorimetry),[8~10].7050200mm[11],DSC500,,().DSC.DSC,DSC.17050200mm,1.1/2DSC(),1mm,10/min470DSC,.DSC550,10/min(),20/min30/min.10/minDSC,07mm,005mm,DSC,.17050()Table1Chemicalcompositionof7050aluminumalloy(massfraction)%ZnMgCuZrFeSiAl62232301401008DSCOLYMPUSGX71SSX-550DSC131.2217050DSC7050200mm1(a).,,,:;.,,.7050200mm(10/min)DSC1(b).,DSC477483.DSC,7050200mm,477,483.27050200mm.,:(21,);(,223).1(a)2,1(a)212材料与冶金学报第7卷,1(a).22.:A,lCuFe3,Al7Cu2Fe;A,lZn,MgCu4,7.22()Table2EDSanalysiscorrespondingtodifferentpointsinFig2(molefraction)%MgAlCuZnFe1-790131-79213967911567-3179601106114-:7050200mm,Al7Cu2FeA,lZn,Mg,Cu.7050Al7Cu2Fe,550[12],DSC550,DSC;7050A,lZn,Mg,Cu477[13],DSC477.:7050477,1(b)483.7050200mmDSC,DSCDSC,DSC.22DSC7050200mm10/min,20/min30/minDSC3.,DSC(20/min30/min),DSC483.DSC20/min,DSC477,483(32).DSC30/min,DSC477(33).,DSC483:20/min,7050200mmDSC477.(10/min),7050200mmDSC477,483.DSC(10/min),4,2,213第3期高凤华等:7050铝合金半连续铸锭在DSC分析过程中组织的变化3.,DSC(),7050200mmDSC477,490.477,477.490,490,DSC483.23DSC7050200mm10/min(DSC)4705.5(a)5(b),7050200mm10/min470,(5(b)13).7050200mm10/minDSC,,DSC,.,DSCAl2CuMg(3),Al,,,Al.[14]Al2CuMg7490.DSC:,490,7050Al2CuMg(S)[15,16].57050(a),(b)10/min470Fig5Backscatteredelectronmiagesof(a)as-castsampleand(b)quenchedsampleafterbeingheatedto470withaheatingrateof10/minof7050aluminumalloy35b()Table3EDSanalysiscorrespondingtodifferentpointsinFig5b(molefraction)%MgAlCuZn1169637194-22144821251793197615189-,DSC,DSC,DSC.3(1)7050200mm,A,lZn,Mg,Cu,477.(2)DSC20/min,,7050200mmAl2CuMg(S).(3)10/minDSC,7050483S,S490.(4)DSC,.(219)214材料与冶金学报第7卷,,,.4(1),.w(B)00015%~0006%,423~347mm;,218%~236%.(2),,,,.:[1],,,.[J].,2008,57(2):134-136.(HEJiang-a,iLIShu-qin,XINQi-bin,etal.Effectofboroncontentonstructureandpropertiesofsuper-highmanganesesteel[J].Foundry,2008,57(2):134-136.)[2].[M].:,2002:125,133.(ZhangZZ.Wear-resistantofhighmanganesesteel[M].Beijing:MetallurgicalIndustryPress,2002:125,133.)[3]El-MahallawiI,Abdel-karimR,NaguibA.Evaluationofeffectofchromiumonwearperformanceofhighmanganesesteel[J].MaterialsScienceandTechnology,2001,17(11):1385-1390.[4].[M].:,1989:162.(CHENXi-jie.Highmanganesesteel[M].Beijing:MachineryIndustryPress,1989:162.)[5].[D].:,2007:33.(GULin-hao.Influenceofchromiumcontentonhighmanganesesteelwithtraceboron[D].Shengyang:NortheasternUniversity,2007:33.)[6],.[M].:,1992:62,95.(LIANGYi-tian,LIUZhen.Alloyingelementsintheapplicationofcastiron[M].Xi'an:Xi'anJiaotongUniversityIndustryPress,1992:62,95.)[7].[M].:,1981:63,70.(MetallurgicalDepartmentofSteelandIronResearchInstitute.Boronsteelstudyseries[M].Beijing:MetallurgicalIndustryPress,1981:63,70.)[8].()[M].:,2000:57.(CUIZhong-q.iMetalscienceandheattreatment(castingandweldingprofessional)[M].Beijing:MachineryIndustryPress,2000:57.)(214):[1]HeinzA,HaszlerA,KeidelC,etal.Recentdevelopmentinaluminiumalloysforaerospaceapplications[J].MaterialsScienceandEngineeringA,2000,280:102107.[2]MondolfoLF.Aluminumalloys:structureandproperties[M].London/Boston:ButterWorths,1976:842-844.[3]TenzlerU,CyrenerE,TempusG.ExperimentalresultsonphasedissolutionandhomogenizationincontinuouslycastAlZnMgCualloys[J].Aluminum,1999,75(6):524-530.[4]PolmearIJ.Lightalloys:metallurgyofthelightmetals[M].EdwardArnold,1981:51-52.[5],,.Al-Zn-Mg-Cu[J].,2000,31(4):339-341.(ChenKH,LiuYZ,LiuHW.Effectoftemperature-incrementalsolutionheattreatmentonthemicrostructureandmechanicalpropertiesofAl-Zn-Mg-Cualloy[J].JournalofCentralSouthUniversityofTechnology,2000,31(4):339-341.)[6]DumontD,DeschampsA,BrechetY.Ontherelationshipbetweenmicrostructure,strengthandtoughnessinAA705