搜索
48 2 Vol.48No.22012 2 211—219 ACTAMETALLURGICASINICAFeb.2012pp.211–219Al–6.3Zn–2.8Mg–1.8Cu ∗ ( , 710072) Al–6.3Zn–2.8Mg–1.8Cu . , ,Al–6.3Zn–2.8Mg–1.8Cu , α(Al) α(Al)+η(MgZn2) η (MgZn2) T (Mg3ZnxCu3−xAl2) Al7Cu2Fe. , η(MgZn2) , S (Al2CuMg). Al–6.3Zn–2.8Mg–1.8Cu . , , 480MPa 490MPa, 0.2% 2.2%. , , , , ! TG146.1# $%A& 0412−1961(2012)02−0211−09MICROSTRUCTURESANDROOMTEMPERATUREMECHANICALPROPERTIESOFAl–6.3Zn–2.8Mg–1.8CuCASTINGALUMINUMALLOYYANGGuangyu,MENGHongshuai,LIUShaojun,QIYuanhao,JIEWanqiStateKeyLaboratoryofSolidificationProcessing,NorthwesternPolytechnicalUniversity,Xi’an710072Correspondent:YANGGuangyu,professor,Tel:13679228998,E-mail:ygy@nwpu.edu.cnSupportedbyNationalNaturalScienceFoundationofChina(No.51071129)andNationalBasicRe-searchProgramofChina(No.2011CB610400)Manuscriptreceived2011–09–15,inrevisedform2011–12–21ABSTRACTThemicrostructuresandroomtemperaturemechanicalpropertiesofmetal–mold–castingaluminumalloyAl–6.3Zn–2.8Mg–1.8Cuwerestudied.Itwasfoundthatthemicrostructureoftheas–castexperimentalalloyconsistsofnearequiaxedα(Al)matrix,α(Al)+η(MgZn2)eutecticandlittleAl7Cu2Feparticlephase.Thephaseconstitutionofthequenchedexperimentalalloywaschanged,theηphasewasdissolvedintoα(Al)matrixandtendedtodisappear,howeveranewphase,S(Al2CuMg),appeared,whichstillmainlydistributedalongtheα(Al)grainboundary.Theopti-mumsingle–agingprocessparametersweredeterminedbyinvestigatingagehardeningresponseoftheexperimentalalloy.Itwasfoundthatthedouble–agingprocesscouldmakethetensilestrengthoftheexperimentalalloyincreasefrom480MPato490MPa,andtheelongationfrom0.2%to2.2%,comparingwiththesingle–agingprocess.KEYWORDSaluminumalloy,solutiontreatment,microstructure,agehardening,mechanicalpropertyAl–Zn–Mg–Cu , * 51071129 2011CB610400 :2011–09–15, :2011–12–21 : !, ,1967 , , DOI:10.3724/SP.J.1037.2011.00579 !, ! , ! ! , #$!!! #[1−4]. $$% # % $ & %&& , ’#’ ’& (% ’ $ ()!(,)%&, *# , ’ ) +*%&(+ + !+) !$! [5,6].Al–Zn–Mg–Cu *+,, % .212*,! 48 %- * #$ %)%$ . +-% &’ +,/0 ()./%1 &-*’ 2’ (!,#,$* ! %%&’3.()$% & Al–Zn–Mg–Cu Æ 4*()+0&’-,α(Al).&. Æ(Zn Mg 1,.0&/,)256400*3)178 /2 -/% 9.η1(MgZn2),S1(Al2CuMg) T1(Al2Zn3Mg3) ,461+ 0 ) *./, & (!,05 * +11%) +-%22 ’3,%%,%[7−10].:3[7]/;,$37055 . 36 4 51(AlCuZn)49Mg32(T1),(AlCuZn)2−3Mg(η1) Al2CuMg(S1),6’455* 8&0,1Al η1)4.Mondal Mukhopadhyay[8] :3-*,7055 $3().)2η,T,S θ1(Al2Cu) ,6’450*+-%&35h0,(). 5 1+2Cu T1 +2Zn S1.Xie [9]27050 %)().3./(Al,ζ–Mg(Al,Cu,Zn)2,S1,θ1,Mg2Si,Al7Cu2Fe Al13Fe4 1.Manish[10]70,7050$% ()8=0&, 7 &8 &/4&+( ,4&+)2Al2CuMg,MgZn2, Mg2Si 51.5?6[11]/;,7050 $3()+α(Al).&,&/α(Al)+Mg(Zn,Cu,Al)24& Al7Cu2Fe1,2460*+-%’ .,05/9 ,η1 94,1,S12η1:.&8,27 @η11&,S1&-*’9 ,/58:90,S1/%2% 30&-*’ $A.Al–Zn–Mg–Cu#’ 2) &0 *’ .,’4 ) &(supersaturatedsolidsolution,SSS),/%*9,5:B06C+:SSS(α)→GP+→η(MgZn2)→η(MgZn2)→T(Al2Mg3Zn3). ()..&5:1(matrixprecipitates,MPt),&85:1(grainboundaryprecipitates,GBP) &/DB07+(precipitatefreezone,PFZ) 2; (!;8 ! ,=-MP,GBP:PFZ/= . ,846=3.;/0 ! /07D81.9= ,E,/8GP+ η1. 56826412$3?9D81[12−15].@=Al–Zn–Mg–Cu 3 3-! ,8F % ,’&8 ./0,F::; 45G&, $%! ’,H&(+$% #$[16,17],()A+,2 !$,/0Al–Zn–Mg–Cu $% :31? .=,,2 ??; ?6 =- , C+,,%%@71 89+ &+,-2.:,2 1 ,$% &! , .B9,()@G1! (+Æ=(@ () D%%:;H& A A,I?5632’-2CB,$%%&B A.C+,:3D/+$( $% ?= A=JK[18].EC,?C:&026%Zn,2.8%Mg,1.9%Cu,0.1%Mn 0.15%Be Al–Zn–Mg–Cu $% ,D8FG (@600MPa,LE@+2%[17,19].DAFMNDBAl–Zn–Mg–Cu $% %, :3, H1 E#$I=?;.GJ-2.8: $% &&% .75FD.:3Al–Zn–Mg–Cu 2$% .22O () ! ,?D/P& $% A= ;JK.QR$Al–6.3Zn–2.8Mg–1.8Cu +?S,:3 $3() 3-! ,HIJ & .,+7+D/P& $% GAK.1’(CDAl–6.3Zn–2.8Mg–1.8Cu *./(E;*’,%)+:Zn6.0—6.5,Mg2.5—3.0,Cu1.5—2.0,Mn0.1—0.2,AlF;.Al–6.3Zn–2.8Mg–1.8Cu #$2G&12kg$HIJB.LT.Al,Zn Mg+B -2$ Æ,Cu Mn*C+./ Al–50Cu Al–10Mn2$ Æ.+($AMg U% VC,+Al–4Be2$2 . Æ(0.10%(E;*’) Be. #$0, Al–5Ti Al–4Zr$)%&,K6M$ NL DM0,720*OÆN 3250* H6.,O$ OP12mm,160mm EPGEKF %-*BKQ.M$R+DEWL.XAl–6.3Zn–2.8Mg–1.8Cu S%- *(E;*’,%)+Zn6.19,Mg2.77,Cu1.78,Mn0.10,Be0.081,Zr0.15,Ti0.14,AlF;.Al–6.3Zn–2.8Mg–1.8Cu ) &2OG$ IYTBLT,U8M +±4*.) &,ZHK[ /300* 830min,KM3) 8 8/J8/0G60—80*N.,GVQ\/+H’10s.O *Q2K].LT,U8M +±5*,GV0K[23hFLTO *. IK $OP8mm, 10mm RS2K[2WilsonWor-pertgroupH2588&Rockwell IK^LT,TL+980N,?G5K[I7M ,HJIUAV U V PF5 J+V+UWIK’E.Al–6.3Zn–2.8Mg–1.8Cu D83-! IK2Zwick150G3KQWLT,TL150kN,GEQ@2mm/min. 4*()3. $OlympusPM–G3N-4*X(OM) JEOLJSM–5800RK$X4*X(SEM)LT.2X’PertPRoMPD&X 7_ ^(XRD)LTXRD*B. .@1 *$OxfordInca&X 7 L^(EDS)LT*B.’SRK; (DSC)*B 2 ‘OYK:Al–6.3Zn–2.8Mg–1.8CuZ[MPYL\]Q aN bO2132UniversalV4.1DTA& *B^LT,M8Q@+10*/min. $Technai30F&T $X4*X(TEM)3.K[ *3’-,Z$7PRP S +0.7mm MQ,U R3S A0.1mm0K$ SX$M^$M&=TEMK[.2’()^*+,2.1Al–6.3Zn–2.8Mg–1.8Cu-./012_3V18Al–6.3Zn–2.8Mg–1.8Cu $34*().V1a(Z, $3()+E ‘&,α(Al)&N[