Texture, 1974,Vol. 1, pp. 233-258.

(C) Gordon and Breach Science Publishers Ltd.Printed in United Kingdom

TEXTURE OF METALS

HSUN HU

United States Steel Corporation, Research Laboratory, MonroevillePennsylvania 15146, U.S.A.

(Received March 1, 1974)

A condensed review ofcasting, deformation, and annealing textures of polycrystalline metals and alloys is presented.It is intended to provide an informative but simplified reference for researchers, engineers, and students who areseeking quick information on the development of textures in various metal objects, and for those who are primarilyinterested in the textures of non-metallic materials, but wish to acquire a general background knowledge on thetexture formation in metals.

INTRODUCTION

Metals are crystalline in the solid state. In a poly-crystalline aggregate each grain is an individualcrystal differing from its neighboring grains inlattice orientation. At any stage of the manu-facturing process, it is seldom that the crystals areoriented completely at random. In castings,columnar grains can form along a specific crystallo-graphic direction during solidification. During sub-sequent plastic deformation, the crystals rotatetoward certain stable orientations. Upon recrystal-lization, new crystals form andgrow preferentially atthe expense of the deformed matrix crystal. Allthese processes lead to the development of non-randomness of the grain orientations in a poly-crystalline aggregate, known as preferred orienta-tions, or textures. The nature of the texturedeveloped in a particular specimen depends on thematerial and on the mechanical and thermaltreatments.Many of the physical, mechanical, and even

chemical properties of single crystals vary with thecrystallographic direction or plane. Accordingly, atextured material usually exhibits anisotropicproperties. Depending on the nature of the textureand the intended use of the material, propertyanisotropy may or may not be a desirable featurefrom the practical point of view. To fully utilize theproperty anisotropy to advantage, it is oftennecessary to "tailor-make" a texture for a particularpurpose. Much research, both industrial andacademic, on the development of textures and theprinciples governing such development has beenconducted in recent years.

233

Data on textures of metals are voluminous in theliterature. In this article, only a brief account oftextures in castings, deformed metals and annealedmetals will be given. For detailed information, thereader is advised to look into the general referenceslisted at the end of the paper. For compactness ofthis presentation, individual references were pur-posely deleted.

CASTING TEXTURES

Structure of Metal CastingsThe macrostructure of a metal casting may varyconsiderably depending upon the conditions duringsolidification. In pure metals, the structure aftersolidification is often entirely columnar, if thefreezing rate is slow and if the metal solidifies withlittle turbulence. The casting structure of solid-solution alloys is usually characterized by regionsof equiaxed grains; in many instances columnarcrystallization may be completely absent. However,the as-cast ingot structure of austenitic Cr-Nialloys, e.g. the 18-8 or 304-type stainless steels, canbe entirely columnar. Hence, the structure of analloy casting depends not only upon the conditionsunder which the liquid metal is cast and solidified,but also upon the composition of the alloy, as wellas its thermal and constitutional characteristics.

In general, the structure of a metal casting maycontain three distinguishable zones: (1) the chill-cast zone in which small crystals of various orienta-tions are formed next to the mold wall; (2) the

234 HSUN HU

columnar zone, which contains elongated crystalswith certain crystallographic directions aligned inthe direction of heat-flow or crystal growth; and(3) the interior equiaxed zone, where essentiallyequiaxed grains are crystallized from the lastportion of the liquid metal in the mold. The chill-cast grains may or may not have a preferred orienta-tion, whereas the orientation of the interiorequiaxed grains is always random. A relativelystrong texture is usually associated with thecolumnar grains. This is attributed to a preferreddirection of growth, which is apparently related todendritic growth due to supercooling, and togrowth competition among the new grains.

tion of the -ferrite can be derived from a [100]orientation of the austenite according to the K-Srelationships. This would imply that the austeniteadopted the orientation of the di-ferrite which frozein a [100] preferred orientation.

In hcp metals the casting texture appears todepend on the c/a ratio. Cadmium and zinc, bothhaving axial ratios greater than that for ideal close-packing (c/a 1.633), develop the same castingtexture. Magnesium has an axial ratio slightly lessthan 1.633; accordingly, its casting texture differsfrom that of Cd or Zn. Castings of other noncubicmetals develop their own characteristic orientations.The casting textures of various metals and alloys

are summarized in Table I.

Texture ofMetal CastingsThe preferred orientations of metal castings differfrom metal to metal, depending mainly upon thecrystal structure of the metal. For cubic (fcc andbcc) metals or alloys, a [100] direction is usuallyparallel to the long axis of the columnar grains, orperpendicular to the mold wall; other crystallo-graphic axes are oriented at random around this[100] direction. Preferred orientations of this natureare commonly called fiber textures; these areusually specified by the crystallographic directionlying parallel to the fiber axis.There are exceptions, although these may be a

consequence of a change in freezing morphologybecause ofcompositional or experimental variations.For example, the columnar grains in Pb castingsnormally have a [100] direction parallel to their longaxis, but in zone-refined Pb after unidirectionalsolidification the common axis is [111]. With asmall addition of Ag (5 ppm by weight), the [100]texture is restored. For A1, raising the pouringtemperature to 860C results in a random castingtexture, instead of the normal [100]-type preferredorientation.Among the bcc metals, iron and steels can under-

go successive phase transformations of di(bcc)--,?(fee) --, (bcc) upon cooling. Their casting textureswould be widely scattered if the twenty-fourcrystallographic variants of the Kurdjumov-Sachsorientation relationships (closest-packed planes anddirections of both phases coincide) for fee -beetransformations occurred with equal probability.However, the casting texture of ingot iron wasreported in 1926 to be [100]. In a continuously castslab of low-carbon steel, the columnar zone showeda preferred orientation of [110]. Such an orienta-

DEFORMATION TEXTURES

Reorientation in Plastic DeformationPlastic deformation occurs in metal crystals by slipor by twinning on certain atomic planes and inspecific crystallographic directions, the so-called"slip or twinning systems." In fee metals, the slipsystems are {111} (110), whereas deformationfaulting or mechanical twinning systems are{111} (112). In bee metals, the slip direction isalways (111), but the slip planes can be {110}, {112}and, perhaps {123} with or without preference,depending on metal or the deformation tempera-ture; twinning occurs on {112} (111). In hop metals,the most common slip and twinning systems are(0001) (11-0) and {101.} (i011) respectively, butother slip planes and twinning systems may alsoprevail depending on the c/a ratio and other factors.The deformation mechanisms in other noncubicmetals are usually more complex, because of lowcrystal-symmetry.Although mechanical twinning induces an abrupt

change in orientation of the twinned material, largeplastic strains are obtained usually by slip. Duringthe slip process, the crystal lattice also rotates so thatthe active slip direction (in uniaxial tension) or theactive slip-plane normal (in uniaxial compression)moves toward alignment with the direction of theapplied stress. As a consequence, the orientation ofthe crystal changes during deformation. In a poly-crystalline specimen, even though the grains areinitially oriented at random, after sufficient deforma-tion most ofthe grains are realigned into a preferredorientation, hence the development of a texture.

TEXTURE OF METALS 235

TABLE I

Casting textures of metals and alloys

Metal or Alloy StructureFiber Axis of

Columnar Grains

Al, Cu, Ag, Au, Ni, PbDilute alloys of Al, Mn, P, Sn in Cu-brassNi-20 wt. % CrNi-base superalloys18-8 type stainless steels

FCC [100]

Cr, Mo, Ingot-FeDilute alloys of Si in FeFe-Ni-AI permanent-magnet alloysFerritic Cr stainless steelsfl-brassLow-C steels (continuously cast slab)

BCC [100]

[110]

Cd (c/a 1.885)Zn (c/a 1.856)Mg (c/a 1.624)

HCP [1010]

[2II0]

Tetragonal 11O]Rhombohedral [111

Nature of Deformation TexturesThe nature of the deformation texture dependsessentially on the crystal structure of the metal, andon the nature and extent ofplastic flow. Many otherfactors, such as composition, initial texture,thermal and mechanical history, and the tempera-ture, rate, and physical constraints during deforma-tion, may all affect the resulting texture to someextent. There have been numerous attempts in thedevelopment of a working theory of deformationtextures, but only limited success has been obtained.

Deformation Textures in Wires or RodsWire and rod produced by drawing, swaging, rod-rolling, or extrusion (constrained tensile deforma-tion) usually develop preferred orientations that areuniaxial or fibrous. One or two specific crystallo-graphic directions are oriented parallel to the wireor rod axis, whereas other crystallographicdirections are distributed more or less at randomaround this axis (fiber texture). Frequently, a pre-ferred orientation may also develop in the radialdirection (cyclic texture). In general, the texture ismore diffuse and complex at the surface than in theinterior. This usually arises from frictional forces

at the surface during forming operations. Thenature of the texture depends essentially on thecrystal structure and on material and processingvariables.

Infcc metals, the fiber texture is usually composedof duplex components, the [111] and [100]. Therelative amount of these two components variesfrom metal to metal. In aluminum, the texture ispredominantly [111 ], whereas in silver a high con-centration of [100] is developed. Lead is reportedlysimilar to aluminum. Other common fee metals,such as Cu, Ni, and Au, develop duplex [111]+[100] fiber textures with various relative concen-trations that are intermediate between those of A1and Ag. With increasing [100] (or decreasing [111])component, these metals can be arranged in theorder of A1, Au, Ni, Cu, and Ag, which is approxi-mately the same as the order of decreasing stackingfault energy. Thus, the variation of fiber texturecomponents in fcc metals appears to be related tothe stacking fault energy of each metal.The addition of alloying elements to a pure metal

usually decreases the stacking fault energy.Accordingly, the relative concentration of the [100]component tends to increase. However, for alloysof very low stacking fault energies, a reverse trendhas been observed. The relative concentrations of

236 HSUN HU

the fiber texture components may be influenced alsoby a number of other factors, such as the amount,the temperature, and the rate of deformation, aswell as the initial texture, the grain size, and thepurity of the material. Recrystallization may occurin a high-purity metal during severe deformation orduring forming at an elevated temperature, and theresulting texture will be affected.Table II summarizes the trend of variation of

fiber texture in fcc metals and alloys. A typicalduplex fiber texture is shown in Figure 1.

TABLE II

Variation of fiber texture components in wires or rods of fccmetals and alloys

Increasing [111] Increasing [100] Trend ofVariation

A1, Au, Ni, Cu, Ag --Irtcreasing deformation (A1, Cu)Increasing deformation (Ag, -brass)Decreasing temperature (Au, Cu, Ag)Increasing solute < 30 Zn, < 5 Sn, or< 30 Ag in Cu)

Increasing solute (> 4 9/0 A1 or > As in Cu)Increasing temperature and strain rate

(extruded A1)

In bcc metals, the fiber texture is a simple [110].No minor components were detected in V, Nb, Ta,Mo, W, or Fe. Bcc alloys, such as plain carbonsteels, silicon-ferrite, and fl-brass, also develop asimple [110] texture.

High-strength, patented eutectoid steel wires havea [110] texture but less sharp than that of Fe wires.This is probably due to the fact that the hardercementite phase disturbs the flow of the ferriteduring drawing, and distorts the ferrite texture.Also, eutectoid steel wires drawn at a low speedshow a slightly sharper texture than those drawn ata high speed.

In hcp metals, there is an indication that the fibertexture ofextruded rods or drawn wires depends onthec/aratio. Inthosemetals having c/a < 1.633 (idealclose-packing), such as Zr, Ti, and Be, the fiber axisis [1010]. For zinc (c/a > 1.633), the c axis is eitherparallel or nearly perpendicular to the rod or wireaxis. In the latter case, there is no preferred align-ment of the directions in the basal plane with therod or wire axis. The axial ratio of Mg is very closeto that of the ideal close-packing. Its fiber-texturecharacteristics are intermediate between those ofZn and Zr, Ti, or Be. However, the textures of Znand of Mg deformed at elevated temperatures, mayinclude complications from concurrent recrystalliza-

(113)0.9

(12)0.9

2533.2 (ttt)

FIGURE Fiber axis distribution chart, or inverse pole figure, for aluminum rod extruded at -196C to91.7 pct reduction at fpm. (McHarque, Jetter, and Ogle, Trans. TMS-AIME, 215, 831, 1959.)

TEXTURE OF METALS 237

tion. Table III summarizes the fiber texturesobserved in hop metals and alloys.Swaged, rolled, or extruded rods of orthorhombie

-uranium have a duplex fiber texture, which can bedescribed as approximately [010] + [410], as shown

in Figure 2. These directions correspond to thepoles of (010) and (110) planes. A cyclic preferredorientation with (001) poles in the radial directionis frequently developed. The relative concentrationsof the fiber texture components vary with tempera-

TABLE IiIFiber textures in wires or rods of hcp metals and alloys

Metal Forming Process Fiber Axis

Zn(c/a 1.856)

Zn-alloy(10 AI, 2Cu, 0.03 Mg)

Drawing

ExtrusionExtrusion

[0001 (low reductions)70 [0001 (high reductions)

[0001]-!-90 [0001]90 [0001

Mg Drawing(c/a 1.624) Extrusion (125C)

Dowmetal Extrusion or drawing(Mg-AI, Mn, Zn) (> 450C)

(< 450C)

90 [0001]80 [0001

[2iI0][1010]

Zr Drawing(c/a 1.589)

Ti Wire-rolling(c/a 1.587)

Be Extrusion or drawing(c/a 1.568) (1100-1150C)

[10i0]

[10i0]

[10i0]

(00t)0

(025) (02t) (010)0 0 (04t) [05|] 15 13.5

13311

I0 1110)

(t00)[1oo]FIGURE 2 Fiber axis distribution chart or inverse polefigure for uranium rod extruded at 500C to 91.7 pct reduc-tion in area. (Jetter and McHarque, Trans. AIME, 209, 291,1957.)

ture and amount of deformation. At low deforma-tion temperatures, the [010] component predomin-ates. Increasing deformation and higher tempera-tures favor the development ofthe [410] component.In nuclear-reactor applications, the anisotropicexpansion and contraction of textured uraniumfuel-rods present serious difficulties. These have tobe overcome by strict control of the textures.

Roll-flattening a wire of some fcc metals or alloyscan produce a tape with a strong [111] texture inthe rolling direction. Such tapes can be used forimproved magnetic, elastic, or plastic properties.

Deformation Textures in Tubes

In tube forming the nature of the texture developeddepends on the relative reductions of wall thicknessand tube diameter. When the wall thickness andtube diameter are reduced proportionally, thetexture is similar to that in a rod or wire. If only thewall thickness is reduced, the texture resembles thatof a rolled sheet (textures in rolled sheets will bediscussed in a later section). Sinking the tube, i.e.,when the tube diameter is reduced without reducingthe wall thickness, tends to develop preferred

238 HSUN HU

directions tangential to the circumference. Since intube forming the reduction ratio ofwall thickness totube diameter can be varied at will, the resultingtexture can be controlled within wider limits inproduction than can textures in wire or rod draw-ing or fiat-sheet rolling. However, published dataon tube textures are rather limited.

Compression Textures

Uniaxial compression produces preferred orienta-tions that are quite different from those producedby simple tension or constrained tension. This arisesfrom the fact that in compression, when deforma-tion occurs by single slip, the active slip-planenormal rotates toward the compression axis, whereasin tension it is the active slip direction that tends toalign with the axis of the applied stress. In the com-pression of a polycrystalline aggregate, wheremultiple slip occurs, the direction of lattice rotationis opposite to that in tension. Thus, the stable end-orientations in tension and in compression aredifferent.The preferred orientation produced by com-

pression-rollingf is a fiber-type texture with thecompression axis as the fiber axis. As in wire or rodtextures, the compression textures offcc metals andalloys are not all the same. For most fcc pure metals,with the possible exception of Ag, the compressiontexture consists of a strong component around[110], a spread from [110] to [113], plus a weakcomponent around [100], while orientations aroundthe [111] axis are nearly absent. For many fccalloys, such as -brasses (10-30 Zn) and Cu-A1alloys (4-8 A1), the 110] componentstillpredomin-ates, the spread is again from [110] to [113], but theminor component is around the [111 axis; orienta-tions near the [100] axis are practically absent.Copper-nickel alloys behave like a pure metal incompression-texture development. These texturalcharacteristics appear to be related to the stackingfault energy ofthe metal or alloy. For bcc metals andalloys, such as Fe and Si-ferrite, the compressiontexture is a duplex [111 + [100], with [111 beingthe major component. Among hcp metals or alloys,the compression texture of Mg and its alloy Dow-metal is [0001]. In compressed or compression-rolled Ti, the [0001] axis is tilted with respect to the

Rolling in a slightly different direction in successive passes.A main feature in compression-rolling is that much largertotal strains can be obtained more readily than in uniaxialcompression.

compression axis; the angle of tilt decreases fromapproximately 30 to 15 with increasing reduction.Hafnium behaves similarly.

Deformation Textures in Rolled SheetsThe description of sheet textures While fibertextures can be adequately described by an axis-distribution chart, or inverse pole figure, which isreadily obtainable, a statistically complete descrip-tion of the orientation distribution in sheet texturesrequires "pole-figure inversion" involving cumber-some mathematical operations. With the help ofcomputers, there has been fair success in this areaduring recent years, and its application is expectedto increase in the future. However, the conventionalpole figure, owing to its relative simplicity indetermination, remains as the most commonmethodfor sheet texture representation at present.A pole figure is essentially a stereographic pro-

jection showing the distribution of a set of {hkl}poles in orientation space. Thus, a uniform distri-bution of poles represents random crystal orienta-tion, whereas dense clusters of poles indicate strongtextures. In the construction of pole figures, it isstandard practice to express the density of poles inunits of the pole-density in a random sample of thesame material. Since polycrystalline sheets usuallydevelop complex textures with considerable orienta-tion spreads, the interpretation of a complicatedpole figure in terms of specific orientations isdifficult and frequently ambiguous. To improve thesituation it is desirable to examine one or twoadditional pole figures determined for other sets ofcrystal planes so that the preferred orientations thatare present and their relative prominence can beascertained.

Sheet textures are usually described by "idealorientations," a simplified means of approximatedescription of preferred orientation. The symbol(hkl)[uvw] is commonly used to designate that theplane (hkl) lies parallel to the plane of the sheet (orrolling plane), and that the direction [uvw] isparallel to the rolling direction.

Forfccmetals, the rolling textures canbe classifiedinto two main types. The copper-type, which can bedescribed as having approximately (123)[21i2]+(146)[.il] as its principal ideal orientations, iscommonly found in most of the fee metals, such asCu, Ni, Au, A1, and Th, etc. The other type, havinga principal orientation very close to (110)[i12], isfound in rolled Ag; hence, it is frequently called thesilver-type. The orientation spreads in the two types

TEXTURE OF METALS 239

R.D.R.D.

"NEAR (146) [’l]

(zzo)[ooz] (.o) [ooq(a) (b)

FIGURE 3 Rolling texture of eltrolytic copper after 96.6 pet reduction in thickness at 25C. The idealorientations for both the copper-type and the silver-type textures are indicated. (a) (111) pole figure, (b) (200)pole figure. (Hu and Goodman, Trans. TMS-AIME, 227, 627, 1963.)

RD

0.5-

1.5-

(lo)

(a) (b)

, (110) [TI2]

FIGURE 4 Rolling texture of high-purity silver (99.999+ pet pure), rolled 91 pct at 0C. Texture determinedat 0C. (a) (111) pole figure, (b) (200) pole figure. (Hu and Cline, J. Appl. Phys. 32, 760, 1961.)

240 HSUN HU

ofrolling textures are also distinctly different. In thecopper-type textures, the orientation spread around(112)[111 is fairly prominent, whereas it is nearlyabsent in the silver-type textures. On the other hand,the orientation spread around (110)[001] is fairlyprominent in the silver-type textures, but very weakin the copper-type textures. There is indication thatRh and Pd develop copper-type .rolling textures,whereas Yb shows the silver-type. An intermediatetexture is indicated by Pt. The rolling textures ofCu and Ag are shown respectively in Figures 3 and4.

It should be pointed out that the differencesbetween the two types of textures appear only aftera moderate amount of deformation and are mainlyin the relative prominence of the texture compon-ents, rather than in their nature. Minor differencesmay also exist among textures of the same type, butof different materials. The two types of texturesrepresent the end-orientations which are related byrotations around two [111] axes, one being the(111) pole in the plane of the sheet and near therolling direction, the other being the (111) pole nearthe normal to the sheet plane tilted toward therolling direction.

Texture transition from the copper-type to thesilver-type can be effected by alloy additions. For agiven solvent metal, complete transition of thetexture usually requires a minimum solute con-centration, which depends on the solute element. Atypical example is the addition of Zn to Cu. Thetexture changes gradually to the silver-type withincreasingsolute concentration, up to approximately10 9/o Zn, as shown in Figure 5. Minor components,such as (110)[001 have been observed to peak out atintermediate Zn contents, a phenomenon approxi-mately similar to the texture reversal in drawn wires.Further additions of Zn cause little change intexture. Thus, the texture of 70-30 brass is quitesimilar to that of pure silver. Hence, the termssilver-type and brass-type are often used synony-mously.On the other hand, the texture of Ni is practically

unchanged by the additions of Fe, even up to 70,although 10 9/0 Mo or 50 9/0 Co added to Ni changesthe texture completely from the copper-type to thesilver-type. The fcc alloy Pu-3.4 at. Ga also has acopper-type texture. The general situation of rolling-texture transition is quite similar to that of fiber-texture variation in fcc metals and alloys. Thetransition is apparently associated with the stackingfault energy of the metal or alloy.

Texture transitions of copper-type silver-type

can also be produced in fcc metals or alloys bychanging the temperature of deformation. Figure 6shows such textural changes in a Type 304L stain-less steel. Similar results were reported for Cu, Ag,and low-Zn brass. The direction of texture transi-tion as affected by varying the deformation tempera-ture is consistent in all cases--a silver-type textureis changed toward the copper-type by raising thetemperature of deformation, whereas a copper-typetexture changes toward the silver-type by loweringthe temperature of deformation. Various theorieshave been proposed for such texture transitions infcc metals. Evidence indicates that mechanicaltwinning and deformation faulting on the {111}(112) systems is largely responsible for the forma-tion of silver-type textures. On this basis, no suchtexture transition should be observed in cross-rolling, and this was confirmed in 70-30 brass (seeCross-rolling textures).Long-range order in Cu3Au was reported to have

some effect on its rolling texture after moderatedeformations, but no detectable difference wasobserved in the rolling texture ofNi3Mn, regardlessof whether it was nearly fully ordered or disorderedprior to rolling.

In all bcc metals the rolling textures are largelythe same and the nature of the texture is notappreciably altered by solute additions. The temper-ature of deformation also has little effect on texture.At low temperatures and in some specific alloyssuch as Mo-35 Re and Ti-209/o V, mechanicaltwinning may occur frequently during early stagesof deformation, but as twinning frequency de-creases with increasing deformation, slip rotationsoccurring in the initially twinned material areessentially similar to those in equivalent grains. Therolling texture of bcc metals and alloys can bedescribed as mainly of (001)[il0] to (l l l) [i 0],corresponding to rotations of up to 55 aroundthe [i10] axis in the rolling direction, plus a lessprominent orientation spread from (112)[110] to(111)[.11 ], corresponding to rotations around anaxis nearly in common with the (011) poles of thetwo orientations (30-35 tilt from the rolling planenormal toward the rolling direction). Figure 7shows the rolling texture of Nb (Cb). The dash anddotted lines are respectively loci of rotations aroundthe axes A and B, indicating the nature of theorientation spreads just described. Essentiallysimilar textures were observed in Fe, V, Cr, Mo,Ta, W, Fe-alloys with A1, Si, Ni, Co, V, and Cr,plain carbon steels, the bcc Ti-18 Nb alloy, and//-brass.

TEXTURE OF METALS 241

242 HSUN HU

R.D. R.D.

(,,,)*- (lit)--C. CD.D.

NEAR (12],) [.[2]

(o) [h2]

.nrnl (lO)[001]

(a) (b)

R.D.

--C.O.

NEAR (125)

NEAR (146)

111o)[i12](112)[]ii](.o) [ooi]

BRASS TYPE COPPER TYPE40=

20

O(112) [i[I]( o) [oo]

200 300 400 500 600 7ROLLING TEMPERATURE,=C

(c) (d)

FIGURE 6 Texture transition in Type 304L stainless steel as a function of deformation temperature.(a) 200C, (b)400C, (c) 600C, and (d)change in texture composition, based on the intensities from (111)reflections. Rolling reduction 90 pet. (Goodman and Hu, Trans. TMS-AIME, 230, 1413, 1964.)

TEXTURE OF METALS 243

RD

ND TD

(a) (b) (c)

FIGURE 7 Texture of niobium as shown by (a) (110), (b) (200), and (c) (222) pole figures. Dashed anddotted lines are loci of rotations around axes A and B respectively, indicating the orientation ranges.(Vandermccr and Ogle, Trans. TMS-AIME, 242, 1317, 1968.)

RDRD

(a) (b)

FIGURE 8 (110) pole figures showing textures of iron and Fe-0.8o Cu alloy, cold-rolled 90 pct after indicatedtreatments. (a) Iron, quenched from 925C, (b) Fe-0.8 Cu, quenched from 925C, reheated to 700C,slowly cooled. (Leslie, Trans. TMS-AIME, 221, 752, 1961.)

244 HSUN HU

The presence of a moderate volume fraction ofsecond-phase precipitates has little influence on thedeformation texture. Figure 8 shows the rollingtextures of Fe and an Fe-0.8 Cu alloy. The latterwas solution-treated, then aged before deformation.However, for a similar reason mentioned earlier forpatented steel wires, the rolling texture of a eutec-toid steel is much weaker than that of mild steels.The rolling texture ofzone-refined Fe is consider-

ably sharper than that of less pure Fe; the (112)[il0] component is strengthened, whereas the(111)[112] component weakened. This may be aresult ofextensive dynamic recovery in iron ofzone-refined purity.

In hcp metals the rolling textures can be classifiedinto three categories, according approximately tothe c/a ratio. For those metals with an axial ratiovery close to that for ideal close-packing, c/a1.633, such as Mg and Co (c/a 1.624), the rollingtexture tends to be (0001)[2110], i.e. the basal planesare nearly parallel to the rolling plane, and a close-packed direction in the basal plane coincidesapproximately with the rolling direction. For metalswith c/a > 1.633, such as Zn (c/a 1.856) and Cd(c/a 1.885), the basal planes tend to be tilted 20to 25 each way from the rolling plane with thetransverse direction as the tilting axis; and a [1010]direction lies in the transverse direction. The rollingtextures ofhexagonal Zr, Ti, Hf, and Be (with c/a1.589, 1.587, 1.581, and 1.568 respectively), allhaving low axial ratios, are very similar. In contrastwith the rolling textures of those metals with highaxial ratios, the basal planes are tilted from therolling plane with the rolling direction as the tiltingaxis. The tilt angle varies from 30 to 40 or evenmore at very high reductions. A [1010] direction isparallel to the rolling direction. Figure 9 shows therolling textures of iodide Ti, typical of low c/ametals.

Alloy additions, interstitial impurities, andtemperature ofdeformation may affect the nature ofthe texture, or the degree of orientation spread.Additions of 2 or more A1, for example, changethe rolling texture of Ti sheet to (0001)[1010]. Achange in deformation mechanism or in dynamicrecovery during deformation would certainlyinfluence the resulting textures.

Orthorhombic -uranium develops complex roll-ing textures which vary with the deformation tem-perature. Cold-rolled U foil has preferred orienta-tions near (102)[010] and (012)[021]. Rolling athigher temperatures produces additional com-ponents, which can be described as approximately

R.D.

(,oio)

0.25 7"-"--

FIGURE 9 Texture of iodide titanium rolle6 94 pct at25C. (Hu and Cline, Trans. TMS-AIME, 4, 1013, 1968.)

(176)[410] and (19)[52]. Figure 10 shows (001)and (110) pole figures for U rolled 87 at 300C.The complexity of U textures arises from the lowcrystal symmetry of the metal; it deforms by anumber of slip and twinning systems that are notcrystallographically equivalent.

Surface textures in rolled sheets Just as in wiredrawing or in any other forming process, frictionalforces between metal and rolls produce surfacetextures differing from those in the interior of thesheet. Under the same rolling conditions, surfacetextures produced by unidirectional rolling aremore pronounced than those developed by reversedrolling in successive passes. The surface texture,aside from being generally more scattered or lesssharp than the interior texture, is frequently relatedto the interior texture by a rotational displacementwith the transverse direction as the rotation axis.In addition to friction, there is evidence that defor-mation zone geometry plays an important role incausing depth-dependent variations in texture.Cross-rolling textures Straight-rolled sheet usuallyexhibits high unequal properties in the longitudinaland transverse directions. Such planar anisotropycan be reduced by cross-rolling. With approxi-mately equal amounts of reduction in two perpen-dicular directions, a highly symmetrical texture isusually obtained. Among the fcc metals, the cross-rolling texture of Cu is mainly (110)[223], plus

TEXTURE OF METALS 245

R.D. R.D.

800

/ oo!11 /-soo \,oo-- /,oo oo--//-oo o00 / 500

tO0 tO0I00 I00 t50

1001) (ItO)(a) (b)

FIGURE 10 Texture of uranium rolled 87 pct at 300C as shown by (a) (001), and (b) (110) pale figures.Intensity in arbitrary units.

I ~(1216)[410][--I 0 ~(19)[52]

(103)[010] (very close to (102)[010]1 ,-(018)[031 (very close to (0i2)[021

(Mueller, Knott, and Beck, Trans. AIME, 203, 1214, 1955).

minor components related to the cube orientation.The cross-rolling texture of an fcc Fe-Ni alloy issimilar to that of Cu. In contrast to its straight-rolling texture, cross-rolled 70-30 brass has essen-tially the same texture as cross-rolled Cu, Figure 11.For bcc metals, such as Fe, low-carbon steel, andMo, the cross-rolling texture is mainly (100)[011]plusminorcomponentsof(111)[.11] and(111)[i10].For hcp metals, Zr has a cross-rolling texture of(0001)[100] with reference to the first rollingdirection, and (0001)[11.0] with reference to thesecond rolling direction. When a hot-pressed Beplate with random grain orientation is cross-rolledat 870-1000C, a (0001) fiber texture is developed,superimposed with (0001)[10i0] orientations withreference to either of the two rolling directions.

ANNEALING TEXTURES

The Annealing Phenomena

During annealing, the microstructure of a deformedmetal undergoes a sequence of changes. According

to the structural features, the progress of annealingis commonly described by three consecutive andoverlapping stages, i.e., recovery, recrystallization,and grain growth. Recovery involves the annealing-out of point defects and the annihilation and re-arrangement of dislocations, which leads to theformation of polygonized subgrains. During thisstage of annealing, there is essentially no change intexture. If the annealing temperature is sufficientlyhigh, recrystallization occurs by the "nucleation"and growth of new grains, which are essentiallyperfect and widely different from the polygonizedmatrix in orientation. These new grains grow at theexpense of the matrix by the migration of high-angle boundaries. Thus, recrystallization is alwaysaccompanied by a large change in orientation inlocal regions. Grain growth usually refers to theincrease of the average grain size upon continuedannealing, after recrystallization is complete. Innormal or continuous grain growth, i.e., the distri-bution of grain size remains essentially unchangedduring the process, there is usually a gradualevolution of the annealing texture. In abnormal,

246 HSUN HU

TEXTURE OF METALS 247

discontinuous, or exaggerated grain growth only afew grains grow to very large size at the expense ofthe fine-grained matrix and there is a large changein annealing texture. This type of grain growth isalso known as secondary recrystallization or graincoarsening, and is usually caused by a finely dis-persed second phase, or a strong single-orientationprimary recrystallization texture. Either of theseconditions can inhibit normal grain growth, butallow a few grains to grow disproportionately. Inthe absence of these inhibitions, and when theprimary grains have grown to a stable size limitedby the sheet thickness, coarsening can also occur bythe growth of those grains having a low surface(gas-metal interface) energy.

Reorientations in Annealing

In general, the deformation texture normallydetermines the recrystallization texture, which, inturn, determines the secondary recrystallization orgrowth texture. Usually, the new texture is relatedto its parent texture by rotations around specificcrystallographic axes. For example, in fcc metalsor alloys, the orientation relationships can bedescribed by [111] rotations of30-40,in bcc metals,by [110] rotations of 20-30; rotational relation-ships of the [100] type are occasionally observed inaddition to these. In hcp metals, reorientations dueto recrystallization can be described by [0001]rotations of about 30, and by approximately[10i0] rotations of 90. These orientation relation-ships correspond to high rates of growth of therecrystallized grains. It is well known that grainboundary mobility depends on orientation.However, exceptions may arise from unidentified

complications. Annealing textures are sensitive tomany factors. For a given material, the thermal ormechanical history of the specimen, the conditionsofthe final anneal (the temperature, the heating rate,the furnace atmosphere, the application of stressduring annealing, etc.), and the presence of minorimpurities may substantially inttuence the annealingtextures.Two main theories have been proposed for the

formation of recrystallization textures. One ofthesesuggests that the recrystallization texture is deter-mined by the orientations of the nuclei formed (theoriented-nucleation mechanism), and the other, bythe orientation-dependence of the rate of growthof the nuclei (the oriented-growth mechanism). Weshall not discuss these theories further.

Annealing Textures of Wires or RodsVarious recrystallization textures havebeenreportedfor fee wires or rods. The discrepancies may resultfrom differences in material composition, theamount of cold work, the progress of annealing, orthe techniques of texture measurements. Availabledata indicate that heavily drawn wires with a singlefiber texture tend to retain their deformationtexture upon recrystallization at a low temperature.This appears to be true for A1, most bcc metals, andhcp Be. Such apparent "retention" of the deforma-tion texture is not necessarily indicative of absenceofreorientationuponrecrystallization, for reorienta-tion involving rotations around the fiber axiswould produce no detectable change in the over-alltexture. Annealing at higher temperatures pro-duces new textures, which may be a result of graingrowth or secondary recrystallization. Reorienta-tions involving the same type of rotations, butaround an axis inclined to the fiber axis, wouldproduce orientations differing from the parent fibertexture. Some of the reported results may be inter-preted in this manner. However, this kind ofreorientation would not produce a unique newfiber texture from a parent texture that is ideallyfibrous (i.e. crystals are oriented at random aroundthe fiber axis); the new crystals would have a widevariety of crystallographic axes aligned with thewire or rod axis.For drawn wires or extruded rods with a duplex

fiber texture, annealing at a low temperature mayenhance one component at the expense of the other,because of differences in the stored energy or in therate of recovery. Reorientation may occur withineach component as a result of recrystallization orsubsequent coarsening.

Table IV summarizes the annealing textures inwires or rods of various metals and alloys.

Annealing Textures ofTubesTo a first approximation, the development ofannealing textures in deformed tubes is frequentlysimilar to that in wires or rods, or in rolled sheets,depending on the nature of the deformation textureof the tube. For copper or brass tubes, cold-rolledor drawn with approximately equal reductions ofdiameter and wall thickness, the [111]+[100]duplex fiber texture is retained, but somewhatscattered, upon annealing. Cold-formed tubes ofZr or Zircaloy having [1010] parallel to the tubeaxis, tend to develop a [110] texture upon anneal-

248 HSUN HU

o

+P +

il

oo

TEXTURE OF METALS 249

ing. Beryllium tubes with a fully recrystallizedstructure after hot extrusion have a [1010] texture.

Annealing Textures of Compression SpecimensCompression-rolled aluminum largely retains itsdeformation texture upon recrystallization, al-though local reorientations due to the formation ofnew grains are evident. Secondary recrystallizationin compression-rolled aluminum and silver produces[111] and [110] textures respectively.

Recrystallization of compression-deformed ironand decarburized mild steel tends to retain themajor deformation texture component [111], andto lose the minor component [100]. Compression-rolled Mo retains its deformation texture afterrecrystallization.

Annealing Textures ofRolled SheetsIn fcc metals, textures resulting from recrystalliza-tion can have a remarkably sharp (100)[001]orientation--the so-called cube texturemor a com-bination of other types of orientations entirelydifferent from the cube orientation, depending uponthe deformation texture. In general, if the rollingtexture is of the copper-type, cube texture is pro-duced by recrystallization. Usually there is a minorcomponent of (122)[215_] orientation, which arisesfrom annealing twins of the cube grains. Figure 12shows cube texture in a heavily rolled, then re-crystallized Cu sheet. A fully developed cubetexture may approach the perfection of a pseudo-single crystal. Conditions favoring the developmentof a sharp cube texture are: (1) a small penultimategrain size, (2) a heavy total reduction, and (3) ahigh annealing temperature. The cube texture isrelated to the copper-type rolling texture by [111]rotations of about 40The copper-type rolling texture may be retained

after recrystallization in a few exceptional cases,such as Cu-19/0 Be, Ni3Mn, and others. It may alsobe partially retained, together with a cube texturecomponent, as in A1 or Ni of low purity. Theretention ofthe deformation texture upon recrystal-lization in most ofthese cases is not entirely a resultof recrystallization in situ; it involves local re-orientations of such a nature that the recrystallizedgrain orientations are the same as a component ofthe deformation texture (e.g. recrystallized grainsformed in the deformation band A have the orienta-tion of the deformation band B, and vice versa).These exceptions are mostly a consequence of

IOO

IOOIOOO

(a)

FIGURE 12 Recrystallization texture of electrolytictough-pitch copper, rolled 96 pet and annealed 5 min at200C, as shown by (a) (111), and (b) (200) pole figures.Intensity in arbitrary units.A IS] 000)[001, (122)[212](Beck and Hu, Trans. AIME, 194, 83, 1952.)

250 HSUN HU

inhibited growth of cube grains caused by soluteimpurities or finely dispersed precipitates; theannealing textures of these materials are usuallysensitive to the prior thermal or mechanical historyofthe specimen.Cube texture in fce metals has been a subject of

great interest, not only for scientific value, but alsofor its industrial importance. It has long been knownthat earing in cup-drawing is associated with thetexture of the sheet, and that cube texture gives earsat 0 and 90 to the rolling direction. Cube texturein Fe-Ni alloys (Permalloy) has been utilized toadvantage in magnetic applications.For those fcc metals or alloys whose rolling

textures are of the silver-type, such as Ag, -brassand some other Cu alloys, the recrystallizationtextures are considerably more complex than thesimple cube texture. Figure 13 shows the texture ofan almost completely recrystallized specimen ofcommon silver. In these pole figures, various idealorientations frequently found in the silver-typerecrystallization textures are indicated for com-parison. For example, in high-purity Ag, theapproximate (120)[.11] orientation is the mostprominent, whereas in 70-30 brass, the (225)[734]or (113)[.i is predominant. Thus, the silver-typerecrystallization textures, although usually havingessential features in common, differ appreciably indetail, depending on material and on purity. In spiteofthese differences, the recrystallization textures arerelated to the deformation texture by [111] rotationsof about 30 or 35 in each case, only the selection ofa particular [111] as the rotation axis being different.The reason for such a different behavior in re-orientation is not clear. However, in no case is thelocation of the intensity maxima of the silver-typerolling textures exactly on (110)[i12], and thedeviations from the exact (110)[i12] orientationvary from metal to metal, or with the purity of thesame metal.For those metals or alloys whose rolling textures

are intermediate between the copper-type and thesilver-type, such as those produced either by alloyadditions or by varying the deformation tempera-ture in texture transition, the recrystallizationtextures are correspondingly a mixture of the cubeorientation and those orientations characteristic ofthe silver-type recrystallization texture. Figure 14shows the recrystallization textures of Cu rolled at

140 and 196C, then annealed 15 min at400C for complete recrystallization. The priorrolling textures of these specimens are quite similarto those of 6 and 10 Zn brasses shown earlier

RD

(a)

RD

(2251 [734]

03o)[oo]

(b)

FIGURE 13 Texture ofan almost completely recrystallizedspecimen of common silver (99.99 pet pure) rolled 91 pet at0C and annealed 15 min at 200C. The (110)[I12] orienta-tion represents the residual deformation texture. (a) (111),and (b) (200) pole figures. (Hu, Cline and Goodman TramTMS-AIME, 224, 96, 1962.)

TEXTURE OF METALS 251

in Figure 5, and so are their correspondingrecrystallization textures.The alloys of Cu with a high solute content of P,

As, or Sb (Subgroup -B elements) appear to beexceptional cases. From a silver-type rolling texture,the major components of the recrystallizationtextures of these alloys are not related to the(l l0) [i 2] -type deformation texture by [111]rotations, but by rotations around the sheet-planenormal, which is a [110] axis.

Secondary recrystallization or grain coarsening,occurs in fcc metals or alloys with cube textureduring annealing at a high temperature. In thesecases, normal growth of the primary grains isimpeded by the very low mobility of their boun-daries, since they are mostly of low-angle dis-orientations. Thus, only a few sufficiently off-oriented grains are able to grow. However, if thecube texture is highly perfect, secondary recrystal-lization may be very difficult because of the lack ofsecondary "nuclei" among the primary grains. Insilver or -brass, grain coarsening usually occursin a more or less gradual manner. These structuralchanges are always accompanied by a change intexture, and the new textures are usually related tothe primary recrystallization textures by [111]rotations of 30 to 40 in a direction opposite to thatoccurring during primary recrystallization. Thus,the nature of secondary-recrystallization textures isessentially similar to that of the correspondingdeformation textures. Secondary grains formed inthin sheets of pure Pt upon annealing at a hightemperature have (111) orientation, as the surfaceenergy of these grains is the lowest.

In bcc metals or alloys, the recrystallizationtextures are largely similar, although the relativeprominence of the various texture components maydiffer to some extent, because of material or pro-cessing variations. In heavily rolled Fe, the evolu-tion of annealing textures may be described asfollows" (1) there is little change in texture whenprimary recrystallization is complete; (2) as graingrowth progresses, the (100)[011] deformationtexture component gradually disappears and apartial fiber component with a [110] fiber axisinclined at about 30 to the sheet-plane normal andtoward the rolling direction emerges; and (3) furtherannealing leads to the development of (111)[il0]and (112)[110] textures. Pole figures representingthese features are shown in Figure 15. Prolongedannealing at 700C may produce a secondary-recrystallization texture of (554)[..5] orientation,

11131 [.Tl|

(a)

(214) [3]131o)[ooqooo)[ool](122) [T2]11131 [T]

(b)

FIGURE 14 (111) pole figures showing the recrystalliza-tion texture of electrolytic copper, rolled 96.6 pet at (a)-140C, and (b) -196C, then annealed at 400C for 15min. (Hu and Goodman, Trans. TMS-AIME,227, 627,1963.

252 HSUN HU

which is very dose (

TEXTURE OF METALS 253

develop recrystallization textures containing(554)[..5], (111)[i 10] and (112)[i 10] components.A (200) pole figure indicating such preferredorientations is shown in Figure 16(a). Successfuldevelopment of this texture depends critically onthe pre-precipitation clustering of A1 and N in thelate stages of recovery, which enhances the forma-tion of recrystallized grains with (111) orientations.When A1 and N are largely precipitated as A1Nprior to cold rolling, the recrystallization texturedeteriorates by a reduction of the desirable (111)[il0] component, and by an increase in the un-

sensitive to compositional and processing variables.Additions or depletions of certain elements in lowconcentrations may influence the.annealing textureconsiderably for a given process. Variations of thethermal or mechanical treatments for a given steelmay change the final annealing texture substantially.Factors favoring the development of an annealingtexture desirable for deep-drawing are" (1) a highhot-rolling finishing temperature (above A3),(2) a reasonably fast cooling rate (low coilingtemperature), (3) a moderately high cold-rollingreduction, (4) a reasonably slow heating rate in the

R.D.

200/ (200)

(a) (b)

FIGURE 16 Recrystallization textures of aluminum-killed steels (a) hot-rolled, cold-rolled 65 pct, thenannealed at 20C]hr to 690C (pancake-shaped grains); (b) hot-rolled, annealed 3.5 hr at 705C, cold-rolled65 pet, then annealed at 20C/hr to 690C (equiaxed grains). (Michalak and Schoone, Trans. TMS-AIME,242, 1149, 1968.)

desirable (100)[011] andother scattered orientations,as shown in Figure 16(b). Aluminum-killed steels ofdeep-drawing quality are characterized by pancake-shaped grains. However, it is the crystallographicorientation, not the geometric shape, of the grainsthat is responsible for the anisotrpoic mechanicalproperties.Much of recent work in this area has been on

texture development in rimmed or unkilled steels.The annealing texture in such steels is highly

final anneal, and (5) a suitable soaking period toallow some grain growth. Annealing in a decarburiz-ing atmosphere or the addition of Ti or Nb tocombine with C and N allow the use of higherannealing temperatures for grain growth withoutphase transformation, and hence, can furtherimprove the texture. Considerable effort has veryrecently been directed to the development of highstrength steel sheets having also good deep drawingcapabilities.

254 HSUN HU

TEMPERATURE, *F1500 1600 1700 1800 1500 1600 1700 1800 1500 1600 1700 1800

121 1231z

TEXTURE OF METALS 255

(i.e., the gas-metal interfaces) of the grains play adetermining role in the selection of secondarygrains. By proper control of prior mechanicalprocessing, which determines the direction of pre-ferred orientation, and of the furnace atmospherein the final anneal, which selects the plane of thegrains, Fe-Si sheets with the (100)[001] cubetexture can be produced. It is also possible toproduce cube- or Goss-textured Fe-Si sheets with ahigh permeability through the influence of orientedA1N particles during secondary recrystallization.

In hop metals and alloys, the recrystallizationtextures of Zn and Mg are essentially the same astheir rolling textures, according to early studies.Later quantitative texture studies on a dilute Znalloy containing Pb indicated a change of thetransverse direction from [1010] to [1120] uponrecrystallization, while the basal pole positions

tures, the annealing textures are distinctly differentfrom the rolling texture. With increasing annealingtime or temperature, the texture undergoes con-tinuous changes, which can be described by thesimultaneous variation ofthree angular parameters,, 6, and fl, as shown in Figures 20 and 21. Thesetextural changes, attributable mainly to normalgrain growth, cannot be related to the parent

(oo)

FIGURE 19 Annealing texture of iodide titanium rolled94 pct at 25C, then annealed at 400C for 3125 min. (Huand Cline, Trans. TMS-AIME, 242, 1013, 1968.)

changed only slightly. This suggests that thereorientation is a [0001] rotation of 30. Berylliumretains its rolling texture after recrystallization. Theannealing behavior of Ti and Zr is quite similar. Atlow temperatures, the nature of the recrystalliza-tion texture is apparently the same as that of therolling texture, although reorientation involvingrotations around [0001] is evident. Figure 19 showsthe texture of iodide Ti comp’etely recrystallized at400C (compare with Figure 9). At higher tempera-

FIGURE 20 Stereographic projection showing the angularparameters on a (10i0) pole figure. , is the angle between therolling plane and (0001), is the angle between the axis oftilt and the rolling direction, and ,8 is the angle between therolling direction and the nearest (10i0) pole. (Keeler andGeisler, Trans AIME., :106, 80, 1956.)

texture by simple rotations. Based on the micro-structural changes and the mechanical softeningobserved during the annealing treatment, it has beensuggested that the observed textural evolution isprobably a result of extensive overlapping of thevarious stages (recovery, polygonization, recrystal-lization and grain growth) in the annealing process.It has also been suggested that the recrystallization

256 HSUN HU

C.D. C.O.

33". 14" 9"()

FIGURE 2] Annealing textures of iodide titanium(a) rain, and (b) 25 rain. Note chages o thetaular parameters , , and resulting rom increasedanealin time. (u and Glin, Tr. TS-AE, 4,

texture of Ti or Zr is a result of "compromisedgrowth" between 30 [0001] and 90 [1010] rota-tional relationships, since both of these orientationrelationships represent high rates of growth in hopmetals.The allotropic transformation (hcp) fl(bce)

occurs in Ti and Zr at approximately 880 and860C respectively with a change in orientationaccording to the Burgers relationships (closest-packed planes and directions of both phasescoincide). Annealing at temperatures sufficientlyhigh in the//-phase region produces a quite differenttexture, as shown in Figure 22. Based on the Burgersrelationships and the same variants for - fl --*transformations, this texture suggests that the -phase had a cube texture upon secondary reerystal-lization.In orthorhombie -uranium, the recrystallizationtexture of rolled sheets can be described approxi-mately by four ideal orientations, (113)[i10],(103)[010], (116)[411], and(100)[010].Among these,(103)[010] is one of the major components of thedeformation texture, which is apparently unalteredafter reerystallization. The relative prominence ofthese four orientations appears to depend upon thetemperature of prior rolling. For specimens rolledat elevated temperatures, the (113)[i 10] orientationdominates the recrystallization texture. Cold-rolledspecimens tend to retain their main deformation

texture (103)[010] upon recrystallization. Figure 23shows the texture of a uranium sheet rolled at300C, then recrystallized at 525C. The recrystal-lization texture components may be related to the

RD

FIGURE 22 (1010) pole figure showing texture of titaniumcold-rolled 99.7 pet, then annealed for hr at 1125C in the/i-phase region. (Keeler and Geisler, Trans. AIME, 206, 80,1956.)

TEXTURE OF METALS 257

R.D.

400 1

(oo)(a)R.Do

0o)(b)

FIGURE 23 Recrystallization texture of uranium rolled87 pct at 300C, then annealed hr at 525C as shown by(a) (001), and (b) (110) pole figures. Intensity in arbitraryunits.

~(113)[I10]~(]03)[O]0]~(116)[41I](100)[010]

(Mueller, Knott, and Beck, Trans. AIME, 203,1214, 1955).

rolling texture by various rotations around the (001)and (010) poles. As is commonly observed in othermetals, grain growth leads to some changes in theannealing texture.

Surface Textures in Recrystallized SheetsThere have been few studies ofthe surface recrystal-lization textures in polycrystalline metals. Based onlimited information from single-crystal investiga-tions, surface recrystallization texture depends onthe surface deformation texture in much the samemanner as does the interior texture. An exampleindicating such a dependence for surface textures isprovided by texture transition in austenitic stainlesssteels. By rolling a Type 304 stainless steel at 800C,a copper-type rolling texture is produced, whichrecrystallizes into cube texture upon subsequentannealing. However, in the surface layer of thestrip the recrystallization texture is not of cubeorientation, because the surface rolling texture isnot of the copper-type. This is due to the fact thatthe temperature at the surface during rolling is con-siderably below 800C. When the strip is rolled in asandwich assembly in which the temperature is moreuniform, cube texture is produced through theentire thickness of the strip upon recrystallization.

Recrystallization Textures in Cross-Rolled SheetsThe reorientations resulting from recrystallizationof cross-rolled sheets are generally the same as instraight-rolled or otherwise deformed specimens.The recrystallization texture of cross-rolled Cu isrelated to the (110)[2.3] deformation texture by[111] rotations of 30. Cross-rolled Mo, beingsimilar to compression-rolled or straight-rolledspecimens in annealing behavior, tends to retain itsmain deformation texture but loses some of theminor components. Recrystallization of cross-rolled Fe occurs first in the minor deformationtexture components (111)[11] and (lll)[il0];recrystallized grains formed in these minor deforma-tion texture components later grow at the expenseof the main deformation texture (100)[011]. Re-orientations in connection with these processes canbe described as [110] rotation of 25-30. Therecrystallization texture of cross-rolled Zr is(0001)[11.0] with reference to the first rollingdirection, and (0001)[10i0] with reference to thesecond rolling direction. This reorientation is thusa rotation around the hexagonal axis normal to therolling plane of 30

258 HSUN HU

REFERENCES1. F. A. Underwood, Textures in MetalSheets, MacDonald,

London (1961 ).2. G. Wassermann and J. Grewen, Texturen Metallischer

lYerkstoffe, 2. Aufl., Springer-Verlag, Berlin (1962).3. Recrystallization, Grain Growth and Textures, ASM,

Metals Park, Ohio (1965).4. I. L. Dillamore and W. T. Roberts, Preferred Orienta-

tion in Wrought and Annealed Metals, MetallurgicalReviews 10, No. 39 p. 271 (1965).

5. C. S. Barrett and T. B. Massalski, Structure of Metals,3rd ed., McGraw-Hill, New York, ch. 19-21, (1966).

6. J. Grewen and G. Wassermann eds., Textures inResearch and Practice, Springer-Verlag, Berlin (1969).

7. D. J. Blickwede, New Knowledge About Sheet Steel,ASM, Metals Park, Ohio (1970).

8. llosciowa Analiza Tekstur, (Proc. International Seminaron Quantitative Analysis of Textures), Cracow, Poland(1971).

9. P. Coulomb, Les Textures dans les Mdtaux de RdseauCubique, Dunod, Paris (1972).

10. Metals Handbook, Eighth ed., Vol. 8, ASM, MetalsPark, Ohio, p. 229 (1973).

11. Texture, An International Journal, Gordon and Breach,New York, since 1972.