Recrystallization microstructures and textures in aa 5052 continuous

Materials Science and Engineering A 385 (2004) 342–351

Recrystallization microstructures and textures in AA 5052 continuouscast and direct chill cast aluminum alloy

Jiantao Liua,b,c,∗, James G. Morrisb

a Material Science and Engineering Laboratory, National Institute of Standards and Technology,Gaithersburg MD 20899-8553, USA

b Department of Chemical and Materials Engineering, University of Kentucky,Lexington KY 40506-0046, USA

c Physics Department, Catholic University of America, Washington DC 20064, USA

Received 4 December 2003; received in revised form 21 June 2004

Abstract

Commercially produced hot bands of AA 5052 continuous cast (CC) and direct chill (DC) cast aluminum alloys were cold rolled to (thickness)r r both theC ion texturei rmined byX ture, anda andD history. Inc ctions priort pendent oft©

K

1

wmaista

s

A

nallu-slab,al

thanctly/orablyherme-n of

struc-ucingibu-thisthe

0d

eductions of 70%, 80%, and 90% followed by annealing at different conditions. The recrystallization kinetics are found equivalent foC and DC materials. Recrystallization microstructures are different between the CC and DC materials. Evolution of recrystallizat

n the CC and DC materials were investigated by using three-dimensional orientation distribution functions (ODFs) that were dete-ray diffraction. The recrystallization texture was correlated with cold rolling reduction (prior to annealing), annealing temperannealing time. Results showed that the R{124}〈211〉 and cube{001}〈100〉 are dominant recrystallization texture components in both CCC materials. During annealing, the intensity and volume fraction of the cube component strongly depend on the prior cold rollingontrast, the intensity and volume fraction of the R component remains almost constant regardless of the different cold rolling reduo annealing. After complete recrystallization, the intensity and volume fraction of both R and cube components appear to be indehe annealing temperature and annealing time.

2004 Elsevier B.V. All rights reserved.

eywords: Aluminum alloy; Recrystallization; Texture

. Introduction

Growth in the automotive industry and the demand foreight reduction of vehicles have opened the door for auto-otive application of Al-Mg (AA 5XXX) alloys. The plasticnisotropy, determined by texture, is of critical importance

n affecting deep drawing properties of sheet products. Con-equently, the challenge to produce Al-Mg sheets with con-rolled anisotropic mechanical properties has drawn muchttention in recent years.

The conventional production of aluminum alloy sheets,tarting from direct chill (DC) cast ingot, includes homoge-

∗ Corresponding author: Alcoa Technical Center, 100 Technical Drive,lcoa Center, PA 15069-0001, USA.

E-mail address:[email protected] (J. Liu).

nization, hot rolling, annealing, cold rolling and an optiofinal annealing. An alternative way for production of aminum alloy sheets, starts from continuous cast (CC)which involves only hot rolling, cold rolling and an optionfinal annealing. Note that CC slab with thickness less25.4 mm, formed from liquid alloys by caster, was direfed into hot rolling mills without any homogenization andprior reduction. Therefore, CC materials compare favorwith DC materials in lower energy consumption and higproductivity. DC material undergoes extensive thermochanical processing that results in significant breakdowthe cast structure. On the other hand, most of the casttures are retained in CC material and are deformed proda banded intermetallic structure in which the spatial distrtion of particles is not uniform. It has been found thatbanded intermetallic structure may significantly affect

921-5093/$ – see front matter © 2004 Elsevier B.V. All rights reserved.oi:10.1016/j.msea.2004.06.070

J. Liu, J.G. Morris / Materials Science and Engineering A 385 (2004) 342–351 343

subsequent recrystallization behavior and texture of Al-Mn(AA 3XXX) alloys [1–3].

Previous investigations of Al-Mg alloys have focused ontexture evolution of the DC materials during hot rolling[4–6],annealing[7–9], and cold rolling[7,9–11]. However, infor-mation about the recrystallization texture evolution of CCmaterials during annealing is still lacking to date. It is there-fore imperative that comparison in recrystallization and tex-ture behavior between CC and DC Al-Mg alloys be made sothat the difference can be highlighted.

This work has been conducted in an effort to studythe recrystallization behavior of commercial AA 5052 (Al-2.4 wt.% Mg) CC and DC materials during annealing. Specif-ically, the effects of cold rolling reduction, annealing temper-ature (TA) and annealing time (tA) on the microstructure andtexture evolutions were investigated. Therefore, it was thepurpose of this work to provide information that enables op-timization of thermomechanical processing parameters forAA 5052 CC material. Another focus of this work was tocompare the microstructure and texture of both CC and DCmaterials during recrystallization.

2. Experimental

2

ithc r-i was4 com-p thea s fol-l e ho-m 0%,a lingp andsa 00 s,2b

2

romt nor-m ldm Thes .P

TC y 100

A

AA e

950 ml water) the samples were electropolished using a so-lution of 15 ml HNO3 and 50 ml HClO4 acids in 950 mlmethanol to remove the deformation layer. The microstruc-tures were examined using light microscopy under polarizedlight. The grain size was determined by a linear interceptmethod.

2.3. Crystallographic texture measurement

Samples for crystallographic texture measurements weresectioned in the rolling plane (normal to the RD and to thetransverse direction (TD)) at the half-thickness position. Thesurface for measurement was carefully polished to minimizesurface stress. Three incomplete pole figures{111}, {200}and{220} were measured (αmax= 75◦) using Cu K� radi-ation by means of the Schulz reflection method[12]. Allincomplete pole figure data were corrected for defocusingerror and background intensity. Three-dimensional orienta-tion distribution functions (ODFs)f(g) were calculated byusing the arbitrarily defined cell (ADC) method[13,14]. Theorientationsgwere visualized in Euler space defined by threeEuler anglesϕ1, Φ, ϕ2in the range of 0◦ ≤ ϕ1, Φ, ϕ2 ≤ 90◦.Each texture component is fitted using a Gauss-type scatter-ing function for quantitative analysis[15,16]. Therefore, thevolume fractionMi of each texture componenti was calcu-l i

mt

M

3

3

0%c theR ,w s ofa theg ever,C icles nti-fi RD,w yd

nib Fs,og rasso on,t ation{ -

.1. Materials and procedures

Commercial alloy AA 5052 CC and DC hot bands wompositions shown inTable 1 were used for the expements. The thickness of the CC and DC hot bands.06 and 3.67 mm, respectively. In order to generate aletely recrystallized microstructure before cold rolling,s-received hot bands were annealed at 823 K for 7200

owed by water quenching. The quenched hot bands werogeneously cold rolled at room temperature to 70%, 8nd 90% reductions in thickness. In the following annearocess, samples were then cut from cold rolled hot bnd annealed at 573 K, 673 K, and 773 K for 20 s, 50 s, 150 s, 550 s, 750 s, 1000 s, 5500 s, 104 s, and 105 s followedy a water quenching.

.2. Microstructure examination

Samples for microstructure examination were cut fhe cold rolled hot bands on planes normal to theal direction (ND) and to the rolling direction (RD), coounted and ground to about 600 grit using SiC paper.

urface of the samples was polished using 1�m aluminarior to anodizing using Barker’s reagent (50 ml HBF4 in

able 1ompositions of experimental materials, as mass fractions multiplied b

lloy Si Fe Cu Mn Mg Zn Cr Al

A 5052 CC 0.13 0.35 – 0.03 2.40 0.02 0.18 BalanceA 5052 DC 0.10 0.39 0.02 0.03 2.39 – – Balanc

ated by determining the central orientationsg0, the maxi-um intensity (height)si(gi0), the scattering widthψi , and

he symmetrical multiplicityZi

i = Zi

2π1/2 si(gi0)ψi

[1 − exp

(−ψ

2i

4

)](1)

. Results and discussion

.1. Microstructure and texture of cold rolled hot bands

Fig. 1 shows the microstructures of hot bands after 9old rolling. The grains are severely elongated alongD for both CC (Fig. 1(a)) and DC (Fig. 1(b)) materialshich characterizes typical deformation grain structureluminum alloys. There is not a significant difference inrain structures between the CC and DC materials. HowC material (Fig. 1(c)) contains a banded constituent parttructure (mostly Al-Fe-Mn crystallized phase that is ideed by energy dispersive spectrometer (EDS)) along thehile the DC material (Fig. 1(d)) is featured by a uniformlistributed particle structure.

Fig. 2 illustrates the ODFs (Fig. 2(a)) and the orientationtensity of orientations along the� fiber (Fig. 2(b)) of CC hotand after 70%, 80%, and 90% cold rolling. For the ODnly three sections ofϕ2 = 45◦, ϕ2 = 60◦, andϕ2 = 90◦, wereiven in order to highlight the Copper, S/R, and cube/Brientations, respectively. After 70% cold rolling reducti

he texture is characterized by a retained cube orient001}〈100〉 accompanied by a well developed� fiber spread

344 J. Liu, J.G. Morris / Materials Science and Engineering A 385 (2004) 342–351

Fig. 1. Grain structure of AA 5052 alloy for (a) CC and (b) DC materialsand particle structure of AA 5052 alloy for (c) CC and (d) DC materials after90% cold rolling.

ing from the Brass orientation{011}〈211〉 through the S ori-entation{123}〈634〉 to the Copper orientation{112}〈111〉.The cube orientation rotates about ND and yields a weakcubeND orientation. During further cold rolling, grains rotatefrom the cube orientation to the Goss orientation{011}〈100〉and then toward the Brass orientation along the cubeRD and� fibers. As a result, the intensity of the Brass orientation in-creases while the intensity of the cube orientation decreaseswith increasing cold rolling reduction (Fig. 2(a)). After 90%cold rolling, the cube orientation disappears. For all three coldrolling reductions, the highest intensity is found at (ϕ1,�, ϕ2)= (65◦, 30◦, 60◦) that is located between the Copper and Sorientations (Fig. 2(b)).

The textures of cold rolled DC hot band are shown inFig. 3(a). At 70% cold rolling reduction, the intensity of the

Fig. 2. (a) ODFs (at sections ofϕ2 = 45◦, 60◦ and 90◦) and (b) the intensityof orientations along the� fiber (skeleton line) of cold rolled AA 5052 CChot band with cold rolling (CR) reductions of 70%, 80% and 90%.

cube orientation of the DC material remains at 6.2, whichis much higher than the CC material at the same reduction.Additionally noted, the intensity of orientations along the�fiber is below 3.5. The cube orientation transforms to the Gossorientation{011}〈100〉 along the RD and further to the Brassorientation through the� fiber with increase in cold rollingreduction in the same way as the CC material. It can be seenthat the cube orientation is retained even after cold rollingwith a 90% reduction. The intensity of the orientations alongthe� fiber (Fig. 3(b)) is lower than that of the CC material.The highest intensity is also found at (ϕ1,�, ϕ2) = (65◦, 30◦,60◦), which is the same as that of CC material. As can be seenin Figs. 2 and 3, the orientation (ϕ1,�, ϕ2) = (65◦, 30◦, 60◦)becomes the strongest orientation along the� fiber, whichindicates inhomogeneous development of the� fiber duringcold rolling in both CC and DC materials. In general, thetexture evolution of DC material appears similar to that ofCC material except that the evolution is delayed in the DC


Fig. 3. (a) ODFs (at sections ofϕ2 = 45◦, 60◦ and 90◦) and (b) the intensityof orientations along the� fiber (skeleton line) of cold rolled AA 5052 DChot band with cold rolling (CR) reductions of 70%, 80% and 90%.

material, which can be attributed to the strong initial cubeorientation in the DC material[11].

3.2. Recrystallization kinetics

The progress of recrystallization during annealing was ex-amined by using microhardness supported by examinationsof microstructure and texture.Fig. 4 presents the change ofmicrohardness versus annealing timetA of CC and DC ma-terials during annealing at temperatures of 573 K, 673 K, and773 K. It can be seen that higher annealing temperature leadsto earlier starting time for recrystallization. The starting timefor recrystallization shifts from about 1000 s at 573 K anneal-ing to about 60 s at 773 K annealing (Fig. 4(a)). The curves ofmicrohardness versus annealing timetA of DC material dur-

Fig. 4. Microhardness vs. annealing time of cold rolled (cold rolling (CR)reductions of 70%, 80%, and 90%) AA 5052 (a) CC and (b) DC materialsat annealing temperatures of 573 K, 673 K, and 773 K.

ing annealing at different temperatures (Fig. 4(b)) are quitesimilar to those of CC materials shown inFig. 4(a). The timerequired for complete recrystallization of AA 5052 CC andDC samples under different cold rolling reductions are givenin Figs. 5(a) and 5(b), respectively. Dash lines indicate thestarting time for recrystallization, while the solid lines indi-cate the time required for complete recrystallization. Whilethe time required for complete recrystallization appears to beindependent of cold rolling reduction for both materials an-nealed at either 673 K and 773 K, the time required for com-plete recrystallization decreases with increasing cold rollingreduction when the annealing temperature is 573 K. Similarresults are also reported for a Al-1.8 wt.% Cu alloy[17]. Ingeneral, there is no remarkable difference of recrystallizationkinetics between CC and DC materials.


Fig. 5. Effect of cold rolling reduction on recrystallization (RX) progress ofAA 5052 (a) CC and (b) DC materials at annealing temperatures of 573 K,673 K, and 773 K.

3.3. Recrystallization microstructure

Recrystallization grain structure of the CC material af-ter 70%, 80%, and 90% cold rolling followed by annealingat 673 K for 1000 s are shown inFigs. 6(a) through 6(c),respectively. They clearly show that recrystallization grainsize decreases with increasing cold rolling reduction priorto annealing, which can be explained by strain induced nu-cleation. It is worth pointing out that there exists a band ofRD elongated grain structures in the CC material at about thehalf-thickness layer as indicated by arrows. The average ratioof the dimension in the RD to the dimension in the ND ofthe grains in the banded structures is about 4:1. This bandedgrain structure was also observed in all other completely re-crystallized samples of the CC material in this work. Char-acterization of this banded grain structure, beyond the scopeof this study, will be presented elsewhere.Fig. 7 shows therecrystallized grain structures of cold rolled DC hot bands.The banded grain structure observed in CC material is absentin the DC material. Instead, an equiaxied grain structure isformed after annealing at 673 K for 1000 s of 70% (Fig. 7(a)),80% (Fig. 7(b)), and 90% (Fig. 7(c)) cold rolled specimens,respectively.

Fig. 6. Grain structure of AA 5052 CC material after (a) 70%, (b) 80% and(c) 90% cold rolling followed by annealing at 673 K for 1000 s.

The recrystallized grain size was averaged between thedimensions in the ND and in the RD. The average recrystal-lized grain size of the microstructures shown inFigs. 6 and 7is plotted versus cold rolling reduction inFig. 8, where solidsymbols stand for the average grain size of grains at the centerlayer (from quarter- to half-thickness), while the open sym-bols represent average grain size of grains at the surface layer(from surface to quarter-thickness). Generally, the average re-crystallized grain size on the surface layer is smaller than thatat the center layer for both the CC and DC materials. For theCC material with 70% reduction, the average recrystallizedgrain size is about 25.5± 1.3�m at the center layer, while


Fig. 7. Grain structure of AA 5052 DC material after (a) 70%, (b) 80% and(c) 90% cold rolling followed by annealing at 673 K for 1000 s.

it is just 10.9± 0.5�m on the surface layer. The average re-crystallized grain sizes at center and on the surface layers ofDC material with 70% reduction is 21.5± 1.1�m and 15.0± 0.8�m, respectively. Therefore, the difference of averagegrain size between surface and center layers for the CC ma-terial is larger than that for the DC material. This difference,however, is significantly reduced with increase in cold rollingreduction prior to annealing. As a result, the differences of

Fig. 8. Dependence of recrystallized grain size on cold rolling reduction ofAA 5052 for the CC and DC materials after annealing at 673 K for 1000 s.

average recrystallized grain size between surface and centerlayers are 7�m and 4�m for the CC and DC materials with90% cold rolling reduction prior to annealing, respectively. Ingeneral, the grain size distribution between surface and cen-ter layers in the CC material is more inhomogenuous thanthat in the DC material.

3.4. Texture evolution during recrystallization

3.4.1. Effect of cold rolling reduction (prior toannealing)

Fig. 9 shows the recrystallization texture of the CC andDC materials after cold rolling followed by annealing. Afterannealing of the CC material, the intensity of the cube orien-tation increases rapidly from 3.1 in specimen with 70% coldrolling reduction to 7.7 in specimen with 90% cold rollingreduction (Fig. 9(a)). For the DC material, the intensity ofthe cube orientation reaches 11.9 in specimen with 90% coldrolling reduction, which increases from 4.6 in specimen with70% cold rolling reduction for the DC material (Fig. 9(b)).The intensity of the R orientation{124}〈211〉 slightly in-creases with increasing cold rolling reduction for both theCC and DC materials after annealing. The copper orientation{112}〈111〉, even though weak, is retained in all samples.These results indicate that the cube is a major recrystalliza-t thec re-c ringa e DCm st ationd

ingt re-t veryr crys-

ion texture component for AA 5052 alloy. Increasingold rolling reduction strongly favors the formation of therystallization texture, especially, the cube orientation dunnealing. Moreover, the retained cube component in thaterial with 90% cold rolling reduction (Fig. 3(a)) appear

o substantially enhance the nucleation of the cube orienturing annealing (Fig. 9(b)).

Beck and Hu[18] proposed two mechanisms explainhe origin of the R orientation: (1) The R orientation isained from the previous rolling texture by extended recoeactions such as continuous recrystallization (in situ re


Fig. 9. ODFs (at sections ofϕ2 = 45◦, 60◦ and 90◦) of cold rolled AA 5052(a) CC and (b) DC hot bands with cold rolling (CR) reductions of 70%, 80%and 90% followed by annealing (AN) at 400◦C for 1000 s.

tallization)[17,19–22]; (2) R orientated grains form throughdiscontinuous recrystallization (genuine recrystallization) bynucleation at the grain boundaries within S oriented grains[21–25]. For the second mechanism, high strains favor theformation of R orientated grains, since they preferably nu-cleate at the grain boundaries[21]. In most cases, both mech-anisms take place by a competition process during annealing.As shown inFigs. 2 and 3, the highest intensity along the�fiber for cold rolled materials is located close to the S orien-tation, where the R orientation (ϕ1,�, ϕ2) = (65◦, 30◦, 60◦)occupies after annealing. The cold rolled CC materials werecompletely recrystallized after annealing at 673 K for 1000 s(Fig. 6). After annealing of the 70% cold rolled material,no remarkable transformation of the ODFs (Fig. 9(a)) wasfound except for weakened deformation textures in compar-

ison with cold rolled material (Fig. 2(a)). In contrast, ODFssignificantly changed upon annealing of 90% cold rolled CCmaterial (Fig. 9(a)) in which the cube texture is well devel-oped as compared to the ODFs of 90% cold rolled CC ma-terial (Fig. 2(a)). ODFs results (Fig. 9) also indicate that ahigher the cold rolling reduction yields a higher intensityof the R orientation after annealing. The above results sug-gest that the retained mechanism overwhelms the nucleationmechanism at 70% cold rolling reduction. However, the nu-cleation mechanism becomes dominant with increasing coldrolling reduction. Similar transition from nucleation mech-anism to retention mechanism is also effective in the DCmaterial (Fig. 3(a) andFig. 9(b)).

The effect of cold rolling reduction on the volume frac-tion of various texture components in CC and DC materialsafter cold rolling followed by annealing at 673 K for 1000 sare given inFigs. 10(a) and 10(b), respectively. For the CCmaterial (Fig. 10(a)), the volume fraction of the cube compo-nent increases from about 5% at 70% cold rolling reductionto about 8% at 90% cold rolling. The volume fraction of theR component, though lower in intensity, is higher than that of

Fig. 10. Effect of cold rolling reduction on the volume fraction of texturecomponents in AA 5052 (a) CC and (b) DC materials after cold rolling (CR)followed by annealing at 673 K for 1000 s.


the cube component. Therefore the R orientation{124}〈211〉is identified as another major recrystallization texture com-ponent as well as the cube orientation. The volume fractionof the Brass component drops by about 4% with increasingcold rolling reduction, while the volume fraction of the Cop-per component remains at a very low level. It can also beseen that the volume fraction for random orientations keepsat about 70%. The volume fraction changes of the DC ma-terial (Fig. 10(b)) appear similar to that of the CC material(Fig. 10(a)). Again, the volume fraction of the R componentis higher than that of the cube component. It can also be seenthat the volume of the cube component increases by about 6%,while the volume fraction of the Copper component drops byabout 6% when cold rolling reduction increased from 70%to 90%. The volume fractions of the Goss and Brass compo-nents are low in the DC material.

3.4.2. Effect of annealing temperatureFig. 11(a) shows the effect of annealing temperature on

the texture evolution of the CC material. While the typicaldeformation texture components Copper, Brass and S areretained at 573 K annealing without recrystallization, re-crystallization texture components cube and R are dominantin samples annealed at 673 K and 773 K. Microstructure(Fig. 6) and microhardness (Fig. 4(a)) results also verifyt coldr DFsr lingt cubeo iza-t alingt theD ls,t ithi cubeo ithi es int e. Ith raturer ubeo byt

ont erei othtD turei thev noti pleter neral,t entsi alingt nentd out4 con-

Fig. 11. ODFs (at sections ofϕ2 = 45◦, 60◦ and 90◦) of cold rolled AA5052 (a) CC and (b) DC hot bands with cold rolling (CR) reduction of 80%followed by annealing (AN) at 573, 673 and 773 K for 1000 s.

dition (Fig. 12(a)), while the volume fraction of the coppercomponent decreases by about 6% for the DC material atthe same condition (Fig. 12(b)). About 4% of the Coppercomponent remains for both materials. It is interesting tonote that the Brass component disappears in the DC material,while about 5% of the Brass component is retained in theCC material after 773 K annealing. In both the CC and DCmaterials, the volume fraction of the random orientationsincreases rapidly from the deformed state (573 K annealing)to the recrystallized state (673 K annealing). The volumefraction of the random orientations, however, remians almostconstant for annealing temperatures higher than 673 K.

3.4.3. Effect of annealing timeFig. 13shows the intensity of the cube and R orientations

versus annealing time of both the CC and DC materials during

hat a complete recrystallization state is achieved for allolled hot bands annealed at 673 K for 1000 s. The Oesults (Fig. 11(a)) indicate that increasing the anneaemperature does not increase the intensity of either therientation or the R orientation if a complete recrystall

ion has already been achieved. Similar effect of anneemperature on the texture evolution was also found inC material (Fig. 11(b)). For both the CC and DC materia

he intensity of the R orientation slightly decreases wncreasing annealing temperature. The intensity of therientation slightly increasing in the DC material w

ncrease in annealing temperature, however, decreashe CC material with increasing annealing temperaturas been reported that increasing the annealing tempeeduces the strength of the R orientation in favor of the crientation[21,22], which, therefore, is merely supported

he results from DC material in this study.Fig. 12illustrates the effect of annealing temperature

he volume fraction of different texture components. Ths not a significant increase in the volume fraction of bhe cube and R components in either the CC (Fig. 12(a)) orC (Fig. 12(b)) materials when the annealing tempera

ncreases from 673 K to 773 K, which indicates thatolume fraction of the cube and R components doesncrease with increasing annealing temperature if a comecrystallization state has already been achieved. In gehe volume fraction of the deformation texture componn both materials decreases with increasing anneemperature. The volume fraction of the Copper comporops rapidly from about 20% at 573 K annealing to ab% at 773 K annealing for the CC material at the same


Fig. 12. Effect of annealing temperature on the volume fraction of texturecomponents in AA 5052 (a) CC and (b) DC materials after 80% cold rolling(CR) followed by annealing for 1000 s.

Fig. 13. Effect of the annealing time on the intensity of the cube and Rtexture components AA 5052 alloy after 80% cold rolling (CR) followed byannealing at 673 K.

annealing at 673 K. It has been shown that the starting time forrecrystallization is about 250 s (Figs. 4 and 5). The intensityof the cube orientation increases with annealing time up to1000 s and thereafter remains stable during further annealing.Note that a complete recrystallization is achieved at about1000 s for both materials (Figs. 4–7). The R orientation, uponforming at about 1000 s, remains almost a constant intensityduring the annealing. These results indicate that the intensityof the cube and R orientations is independent of annealingtime if complete recrystallization is achieved.

The effect of annealing time on the volume fraction ofvarious texture components in CC (Fig. 14(a)) and DC(Fig. 14(b)) materials are quite similar. The volume frac-tion of all texture components significantly changes between250 s and 1000 s, when recrystallization occurs. It can be seenthat volume fraction of the cube, R and random orientationsincreases, while the volume fraction of the Brass, S, and Cop-per decreases. For both the CC and DC materials, the volumefraction of the cube and R orientations remains almost con-stant after a complete recrystallization state is achieved at

Fp(

ig. 14. Effect of the annealing time on the volume fraction of texture com-onents in AA 5052 (a) CC and (b) DC materials after 80% cold rollingCR) followed by annealing at 673 K.


1000 s. Further annealing beyond 1000 s does not lead to aremarkable change of the volume fraction of various texturecomponents. The volume fraction of the R orientation, whichis about 13% after complete recrystallization for both mate-rials, is higher than that of the cube orientation although theintensity of the R orientation is lower than that of the cubeorientation. About 4% of the Copper component is retainedin both materials.

4. Conclusions

The recrystallized grain size of AA 5052 alloy is stronglyaffected by cold rolling reduction prior to annealing. The re-crystallized grain size can be significantly refined by increas-ing cold rolling reduction prior to annealing. A banded re-crystallized grain structure layer with elongated grains alongthe rolling direction is found in CC material.

The R{124}〈211〉 and cube{001}〈100〉 orientations aredominant recrystallization texture components in AA 5052alloy. The volume fraction of the cube orientation increaseswith increasing cold rolling reduction prior to annealing. Theintensity of the cube orientation is higher in AA 5052 DCmaterial than in AA 5052 CC material.

During annealing, the most important recrystallizationt tions ate isa ntlyc or in-c

A

t ofE ate-f ared , the

Department of Commerce, or the United States Government,nor does it imply that the identified equipment or software isthe best available.

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[ 5)

[[ .[[ 96)

[[[ -

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exture evolution occurs before a complete recrystallizatate is achieved. Once the complete recrystallization stchieved, the recrystallization texture can not be significahanged by either increasing the annealing temperaturereasing the annealing time.

cknowledgements

Financial support from the United States Departmennergy (under Contract No. DE-FC07-01ID14193) is gr

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